What if: Operation Green invasion of Ireland

agree with majority view any invasion would be fail ... however ... https://en.wikipedia.org/wiki/Plan_Kathleen striking ONLY at Northern Ireland, with forces moving to Republic to seek internment?

might it be enough to provoke GB into actions against Republic? which would be counterproductive

Any German forces trying that in NI were going to get hammered by forces already in place and bring in Ireland alongside the Allies anyway.
Just for example as to the planing on the Allied/Irish side:
https://en.wikipedia.org/wiki/Plan_W

yes ... was stating it would be failed "invasion" but the planning you mentioned had (from Irish side) contingency to defend against British as well https://en.wikipedia.org/wiki/Plan_W#Irish_defence_status

am not predicting any great shooting war between Irish and British but if British decided to occupy all or parts of Republic in response to German operation (and subsequent surrender to Irish) it could tie up some fair number of forces.
 
yes ... was stating it would be failed "invasion" but the planning you mentioned had (from Irish side) contingency to defend against British as well https://en.wikipedia.org/wiki/Plan_W#Irish_defence_status

am not predicting any great shooting war between Irish and British but if British decided to occupy all or parts of Republic in response to German operation (and subsequent surrender to Irish) it could tie up some fair number of forces.

Yes there was planning to deal with a British attack however UK forces following a German force into the Free State isn't really the same as a hostile act against the Free State themselves. It makes zero sense for the UK to treat the Free State as a hostile nation in this situation, as has been pointed out it actually suits them to treat it as the Allied Victim, it gets them vastly more long term, and the senior leadership on both sides know that.
 
agree with majority view any invasion would be fail ... however ... https://en.wikipedia.org/wiki/Plan_Kathleen striking ONLY at Northern Ireland, with forces moving to Republic to seek internment?

might it be enough to provoke GB into actions against Republic? which would be counterproductive
Plan Kathleen was, frankly, even nutter than Operation Green. Even the Germans didn't take it seriously.
The claimed IRA strength (3,500 in Éire and 1,500 in NI) were utter nonsense and they sorely lacked for arms. Further given that both the UK and Irish authorities had the "plan" available shortly after the Dunkirk evacuation in MAY1940 (the earliest possible invasion period) it had very little value. In fact they led to increased joint planning for the contingency of a German invasion.
 
Bit of extra info taken from the War Cabinet Minutes through to the end of July 1940, beyond that point the discussions about Ireland appear to focused mainly on trade negotiations.

20th June 1940, W.M. 173 (40) - Defence of Ireland.
(Previous Reference: W.M. (40) 168th Conclusions, Minute 5.)

9. The Minister of Health said that, in the course of the 3 1/2 hours' conversation which he had held with Mr. de Valera on Monday, the 17th June, he had impressed on the latter that the war against Germany was one in defence of the freedom of every democratic country, including that of Ireland, and that His Majesty's Government thought that Eire was in imminent danger of invasion by Germany. Their reasons for this were—

(a) That there was evidence from the "Held" papers and other documents that there was a plan for the invasion of Ireland;

(b) That the experience of other neutral countries showed that Germany did not hesitate to use this weapon against her enemies; and

(c) That Eire was next on the list of neutral countries through whose territory an attack could be launched against Great Britain.

His Majesty's Government were grateful to Mr. de Valera for having agreed to the staff conversations which had taken place; but the measures agreed on were not nearly enough to ward off the lightning attack which Germany was likely to make. The enemy was now in possession of the West Coast of France, on which he could base a seaborne attack. Troops landed by parachutes or aeroplanes could easily swoop upon Irish territory, which was sparsely populated and ideal for the purpose. Moreover, the large number of German citizens and members of the I.R.A. at large would provide an effective Fifth Column.

Irish troops were not sufficient to deal with ruthless attacks on the German model, and, under the plan drawn up by the military advisers of the two countries, reliance would be placed on (a) the vigilance of British naval patrols (which could not use the ports of Eire); and (b) the arrival of reinforcements from Northern Ireland, whose support might well be hindered or prevented by the sabotage of road and rail communications.

In these circumstances, the view of His Majesty's Government was that there was great danger of the Germans being able to carry out an effective landing by sea and air; that they could overwhelm the resistance of the Eire troops; and might be in effective occupation of the Twenty-six Counties within a few hours from landing. The wisest course for Eire would be the immediate abandonment of her neutrality and complete co-operation with us in resistance to Germany. This advice was given in the interest of Eire herself, because, although an invasion of that country would embarrass us, it would be disastrous to her. To this suggestion Mr. de Valera had returned an emphatic negative. He said that the whole force of public opinion was against any abandonment of neutrality a moment before it was inevitable.

He (Mr. MacDonald) had then asked whether it was possible for the Eire Government, with the support of the Opposition, to invite British warships to use Irish ports, and to call in British troops to guard strategic points in the defence of Eire's neutrality. Mr. de Valera had replied that there was no possibility of agreeing to this course, as the national unity which had been achieved between the various parties in the country was based on the continued maintenance of the policy of neutrality and on a firm resistance to the forces of either belligerent who became the aggressor. To permit the occupation of Ireland by the forces of one belligerent would provoke Hitler to carry out his aggressive schemes; it would destroy the national unity which had been achieved with such difficulty in Ireland. It would make no difference to his answer whether the forces which came in were British, French, Polish or Dominion troops. The position might have been different if there had been a United Ireland.

Mr. MacDonald had then suggested that a step might be taken towards the project of a United Ireland by the establishment of a joint council for the defence of the whole island. This, however, Mr. de Valera had rejected as a step involving a decisive breach of neutrality and as a blow to the national unity of Eire.

The further suggestion was then put to Mr. de Valera that something could be done to improve the immediate prospect by arresting and imprisoning the I.R.A. leaders and by interning suspect Germans and Italians. He had replied that, while all the leaders of the I.R.A. outside Dublin were under detention, the authorities could not lay their hands on all the prominent I.R.A. members in Dublin itself. As regards Germans, the documentary evidence available had not been sufficient to establish a conspiracy against the State, and there was no evidence of an unneutral act in favour of one of the belligerents.

Mr. de Valera had made it plain that the Irish people intended to put up a stout resistance to any invasion from whatever quarter; he had asked whether material assistance could not be afforded in the shape, for example, of anti-tank weapons and aircraft. To this Mr. MacDonald had replied that we were not confident of the power of the local forces in Eire to prevent any material we might supply from falling into the enemy's hands. We would, of course, send help the moment we were asked to do so, but, in the circumstances which had been envisaged, this might have to be limited to the operations of our Air Force.

Summing up his impression of the interview, Mr. MacDonald said that Mr. de Valera was undoubtedly impressed with the view of His Majesty's Government as to the imminent danger of an invasion of Eire, which had previously been represented as somewhat of a bogey. He would, however, emphasise his conviction that in his determination to resist either that Mr. de Valera was genuine belligerent to the utmost limit of his power; this resistance would be directed against any attempt on our part to seize the Atlantic ports by force.

The Lord President of the Council said that the War Cabinet were greatly indebted to the Minister of Health for the skill with which he had carried out his tasks; he had evidently succeeded in instilling some sense of reality into Mr. de Valera. The latter, however, had repeated the old theme that he could do nothing to prejudice his country's neutrality, on which his much-vaunted "national unity" depended.

The Lord President had seen a preliminary draft of an Aide-memoire from the Chiefs of Staff, which included the statement that there could be no security for Eire or- the United Kingdom unless proper arrangements were made which included the presence of British or Dominion troops and Air forces in Eire, and His Majesty's Ships in Irish ports. It was further pointed out that the main, and perhaps the sole, obstacle to such collaboration was the partition question.

The Lord President said that, on the basis that help to Eire after invasion had taken place might well come too late, we were compelled to consider the question of entering the Irish ports by force.

At the same time, before this step was taken he would advocate further exploration of the ground, in view especially of the possible unfavourable reaction which would be caused in the United States of America by any forcible measures against Ireland. He would, therefore, propose that the Minister of Health should return to Dublin and should speak to Mr. de Valera on the following lines: —

His Majesty's Government are satisfied that there is no possibility of making your country safe against German invasion, of which it stands in imminent danger at present, unless—

(i) you give the British Navy the use of the Irish Atlantic ports;

(ii) you allow our troops and Air forces to enter the Twenty-six Counties before the invasion occurs; and

(iii) you secure yourself against the dangers of fifth column activities by interning all the leaders of the I.R.A. still at large, as well as any suspicious Germans and Italians at present in this country (we should not press them necessarily to sever diplomatic relations with Germany).

The Minister of Health would go on to ask whether, in return for these measures, Mr. de Valera would be content to accept a declaration stating that His Majesty's Government were, in principle, in favour of the establishment of a United Ireland. This would naturally have to be followed by an. approach to Lord Craigavon, who would have to be told that the interests of Northern Ireland could not be allowed to stand against the vital interests of the British Empire. Lord Craigavon would naturally ask whether the United Ireland would form part of the British Empire. The answer to this was clearly in the affirmative, though of course full Dominion status carried with it the right to secede from the Commonwealth.

Should Mr. de Valera still maintain a negative attitude, the Minister of Health should insist that the proposition should be put to his Government, some members of which he (the Lord President) understood were likely to take a less rigid view.

If the Irish Governments refusal were still maintained, His Majesty's Government would be on stronger ground vis-a-vis the United States of America, if later on they were compelled to use force. He understood that the Chiefs of Staff had not yet studied the question whether we could successfully occupy the Irish ports in the face of resistance and thought that this question should receive early consideration.

The Prime Minister, while agreeing generally with the Lord President, said that we must avoid putting undue pressure on the loyal province of Ulster. He would not urge those who had worked self-government loyally within the Empire to join with those who wished to stay outside it. He was not convinced that the military situation was so serious as it had been represented. He was in favour of allowing the enemy to make the first move; if they succeeded in establishing themselves in Ireland our forces should then be ready to pounce upon them. The whole of Ireland, including Mr. de Valera, would in those circumstances be on our side.

The Lord President of the Council said that he had suggested the possibility of urging this course very strongly upon Northern Ireland only because he was impressed with the dangers to this country which might follow a successful invasion of Ireland.

The Lord Privy Seal said that a German invasion would furnish the best chance of securing a united Ireland, and he saw no advantage in attempting to coerce either Northern Ireland or Eire by force.

The Secretary of State for Foreign Affairs shared the views expressed by the Lord Pri^y Seal, and suggested that the Minister of Health should return to Dublin where he could continue the process of educating Mr. de Valera as to the dangers of invasion, at the same time exploring to what extent any advance towards a United Ireland would help Mr. de Valera in dealing with Irish opinion on this matter. If anything useful came out of these conversations, it would, of course, have to be put to Lord Craigavon.

The Minister without Portfolio thought that, after the experience which this country had had of air-raids during the two previous nights, the Irish people would be in little doubt as to the determination' of Germany to concentrate attacks on this Island. American public opinion was a decisive argument against a forcible seizure of the Irish Ports.

The Secretary of State for the Home Department and Minister of Home Security said that the Irish people were resolute fighters, and he thought that they would be capable of dealing with parachutists or airborne invasion. Difficulties might arise in the case of a seaborne attack, and he suggested that the Irish might be advised to protect their ports by mines, net, and boom defences, which would create difficulties for the invader. He thought that it was impossible to coerce either Northern or Southern Ireland, and that it was unlikely that any substantial advance could be made towards the project of a United Ireland.

The War Cabinet agreed—

To invite the Minister of Health to resume his conversations with Mr. de Valera on the lines suggested by the Secretary of State for Foreign Affairs.

25th June 1940, W.M. 182 - Ireland.
Defence negotiations.

(Previous Reference: W.M. (40) 173rd Conclusions, Minute 9.)

1. The War Cabinet had before them a Memorandum by the Lord President of the Council recording the results of the Minister of Health's second visit to Mr. de Valera, and setting out the alternative possibilities (W.P. (40) 223). The Memorandum suggested that a written communication should be made to Mr. de Valera asking him what would be the attitude of his Government to a specific plan to which we would be willing to do our best to obtain the assent of the Ulster Government. The main inducement included in the plan was the suggestion that certain equipment should be made available, provided that the scheme as a whole was adopted.

After a short discussion, the War Cabinet—

(1) Approved the proposals set out in the Lord President of the Council's Memorandum, and invited the Secretary of State for Dominion Affairs to draw up a communication on the lines proposed.

(2) Invited the Minister of Health to take the communication to Dublin himself, and there await the reply of the Eire Government.

(3) Agreed that, while the proposed communication did not go beyond asking Mr. de Valera what his attitude would be to the plan suggested, it was liable to be represented as an offer. Accordingly, the Lord President of the Council was invited to write to Lord Craigavon informally, indicating to him in broad outline the nature of the communication being made to Mr. de Valera.

28th June 1940, W.M. 186 (40) - Ireland. Defence negotiations.

(Previous Reference: W.M. (40) 182nd Conclusions, Minute 1.)

1. The War Cabinet had before them the text of the Memorandum taken by the Minister of Health to Dublin on the 26th June, 1940, embodying the proposals made by the Lord President of the Council and approved by them on the 25th June. The Ministers discussions with Mr. de Valera, Mr. Lemass and Mr. Aiken, on the evening of the 26th June and on the 27th June were summarised in telegram No. 65 from the United Kingdom representative in Eire. The War Cabinet also had before them the text of a further Memorandum which it was proposed should be communicated to Mr. de Valera, setting on record certain modifications made in the Memorandum of the 26th June. The Lord President of the Council said that, as agreed at the Meeting of the War Cabinet when this matter had last been discussed, he had written to Lord Craigavon, indicating to him the nature of the plan outlined in the Memorandum which had been handed to Mr. de Valera. The reply received had been to the effect that Lord Craigavon was shocked to learn that negotiations were being carried on behind Ulster's back. Such an accusation was, of course, entirely unjustified. All that the Government had done was to enquire what would be the attitude of the Government of Eire towards a certain plan. It had throughout been made clear that it would be necessary to obtain the assent thereto of the Government of Northern Ireland.

It was agreed that a reply should be sent to Lord Craigavon by the Lord President emphasising that Northern Ireland's position was entirely protected.

In discussion, the view was generally expressed that there was little chance that the Eire Government would agree to the present plan, even with the modifications proposed. In theory it was perhaps rather objectionable to modify the scheme to the extent of not requiring a declaration of war by Eire; but in practice the scheme would still secure to us the facilities which we required to guard against a sudden attack. Nevertheless, it was agreed that it would be right to make the further communication now proposed. The fact that we had been prepared to go so far in the negotiations would put us in a very strong position, e.g., in regard to opinion in the United States of America.

The Minister of Health said that he thought there was a minority in Mr. de Valera's Cabinet who would be ready for discussions on the basis of the plan outlined. The modifications now proposed in the plan would be helpful to this minority, but he feared that it was unlikely to affect the majority view.

The War Cabinet –

1) Approved the despatch to Mr. de Valera of the further Memorandum circulated to the War Cabinet.

(2) Invited the Lord President of the Council to reply to Lord Craigavon.

1st July 1940, W.M. 189 (40) - Eire.
Assistance in the event of German attack.

(Previous References: W.M. (40) 151st Conclusions, Minute 13, and W.M. (40) 186th Conclusions, Minute 1.)

9. The War Cabinet had under consideration a Memorandum by the Secretary of State for Dominion Affairs on Assistance to Eire in the event of German attack (W.P. (40) 228).

In the discussion which ensued the following points were made:—

(i) Eire, as a neutral State, was responsible for preserving her neutrality. If she were invaded, we would be entitled to take action by the despatch of troops to prevent the violation of her neutrality,

(ii) If Eire were invaded, it would be desirable that we should immediately take action,

(iii) On the other hand, we must be careful not to be stampeded into taking action on a report of invasion which was either false or of insufficient importance (e.g., the landing of a few parachutists) to justify the despatch of troops into Eire.

The War Cabinet agreed as follows:—

(a) If the General Officer Commanding-in-Chief, Northern Ireland, was satisfied that a serious invasion of Eire had taken place which called for the intervention of the troops under his command, he was authorised to take action forthwith without obtaining Ministerial authority from London.

(b) If the General Officer Commanding-in-Chief, Northern Ireland, received information that Eire's neutrality had been violated, but was uncertain (a) as to the authenticity of the information, or (b) whether the situation justified his intervention, he should refer to London for Ministerial authority.

(c) If the General Officer Commanding-in-Chief, Northern Ireland, received a request for assistance, from the Eire Government through the United Kingdom Representative in Dublin, he was authorised to accept it without reference to London.

(d) The Secretary of State for War was invited to convey instructions in this sense to the General Officer. Commanding-in-Chief, Northern Ireland; and the Secretary of State for Dominion Affairs was invited to inform the United Kingdom Representative to Eire accordingly.

2nd July 1940, W.M. 191 (40) - Eire.
Defence negotiations.

(Previous References: W.M. (40) 189th Conclusions, Minute 9, and W.M. (40) 186th Conclusions, Minute 1.)

11. The Lord President of the Council reminded the War Cabinet that a further Memorandum had been sent to Mr. de Valera, setting on record certain modifications in the Memorandum of the 26th June. This further Memorandum had been sent to Eire on Saturday, the 29th June, and the reply had been expected on Monday, the 1st July. He had made enquiries, and had been told that the Eire leaders were working on their reply, which they hoped to send in two or three days. He had gathered, however, that they did not mean to accept our proposals. It looked as though the Government of Eire were taking the view that Germany was invincible. It might well be that, not only would they not be prepared to invite our forces into Eire before a German invasion, but that if and when invasion took place their forces would offer no real resistance. He thought it his duty to report this to the War Cabinet.

The War Cabinet took note of this statement.

Certain further discussion as to the defence of Ireland is recorded in the Secretary's Standard File of War Cabinet Conclusions.

6th July 1940, W.M. 195 (40) - Eire.
Defence negotiations.

(Previous Reference: W.M. (40) 191st Conclusions, Minute 11.)

11. The Lord President of the Council said that he had circulated a copy of the reply received from Mr. de Valera to the communications made to him on the 26th and the 29th June (W.P. (40) 251). This reply was a flat refusal. He proposed to inform Lord Craigavon that the negotiations had come to an end.

The War Cabinet — Took note of this statement, and authorised the Lord President of the Council to inform Lord Craigavon that the negotiations with the Eire Government were now at an end.

19th July 1940, W.M. 208 (40) - Eire.
(Previous Reference: W.M. (40) 195th Conclusions, Minute 11.)

6. The Lord President of the Council gave the War Cabinet the latest information in regard to the position in Eire. It was evident that the atmosphere between this country and Eire had greatly deteriorated in recent weeks, mainly on account of suspicions entertained in Eire that we had planned to occupy that country by force at an early date. In a recent conversation with Mr. de Valera, Sir John Maffey had been able to go some way to remove these suspicions. It was clear that if we furnished Eire with certain equipment which would enable her to put up a more effective defence against an invasion by Germany, this would greatly help to remove suspicions. The Secretary of State for Dominion Affairs would shortly be circulating a Paper putting forward suggestions on these lines.

The War Cabinet took note of this statement.

22nd July 1940, W.M. 209 (40) - Eire.
(Previous Reference: W.M. (40) 208th Conclusions, Minute 6.)

(Previous Reference: W.M. (40) 195th Conclusions, Minute 11.)

9. The War Cabinet had before them a Memorandum by the Secretary of State for Dominion Affairs (W.P. (40) 274). The Secretary of State for the Dominions said that he had received a.Report from Sir John Maffey to the effect that recently relations with Eire had deteriorated. This deterioration had been mainly due to—

(i) the suspicions in Eire that we proposed to invade that

country;

(ii) our refusal to help them with the supply of munitions;

(iii) articles in the press commenting on the folly of Eire's

neutrality.

In order to remedy the situation he proposed that a public declaration should be made to the effect that we had no intention of sending our forces into Eire without a request from their Government, and, also, that we should offer to the Eire Government a certain amount of military equipment. Such a declaration would, he thought, remove the suspicions in Eire that we intended to enter the country. Until these suspicions had arisen, our relations with Eire had shown a great improvement, and their Government had made a number of concessions which some time ago would have been out of the question. For instance, they had turned a blind eye to the infringement of neutrality by our naval vessels and aircraft; had agreed to the removal of cables to the United States, which now went from this country; and had taken part in Staff talks. If nothing were now done to remove the suspicions of Eire regarding our intentions, our relations would continue to deteriorate and they would be less willing to co-operate in future.

The following points were made during the discussion :—

(i) There was a great difference between a statement made privately and a public declaration. A public declaration on the lines suggested would be liable to be differently interpreted by the Irish and ourselves. Again, any statement which could be taken as implying that in no circumstances would we send our forces into Eire, except at that Governments invitation, would be lacking in frankness, since circumstances might arise which would compel us to do so.

(ii) To meet this point it was suggested that the declaration should be limited to a declaration of our present intentions; and that if, for example, Mr. de Valera did not carry out his declared intention of defending Eire against the German invasion, it would be open for us to deal with that new situation on its merits.

(iii) We had originally proposed to supply military equipment to Eire as part of the comprehensive plan which they had rejected. There was a risk that, if we supplied arms, they might be captured by the Germans or used by the Irish against ourselves. Further, the withholding of arms might well be the most effective way of bringing the Eire Government to a greater realisation of their dangers.

(iv) The Chief of the Imperial General Staff said that, from. the military point of view, he regarded Eire as a potential ally and believed that' they would fight if invaded by Germany. It was in our interest to help them to do so.

(v) It had been suggested that the Government of Eire would probably accept instructors with any anti-aircraft guns which we supplied to them. If they did, this materially altered the situation, since this would represent an extension of co-operation in defence.

(vi) Even so, there could be no question of sending equipment at this stage on the scale proposed as part of the plan which the Eire Government had rejected.

The War Cabinet -

(1) Agreed that action should be taken to damp down the press campaign.

(2) Decided that a public statement on the lines proposed should not be made.

(3) Invited the War Office to prepare, for consideration by the War Cabinet, a list of equipment which might be supplied to the Eire Government at this juncture, on a more limited scale than previously proposed.

26th July 1940, W.M. 213 (40) - Eire.
Supply of equipment.

(Previous reference: W.M. (40) 209th Conclusions, Minute 9.)

11. The War Cabinet had before them a Memorandum by the Secretary of State for War (W.P. (40) 285), to which was annexed a list of the equipment which it was suggested might be supplied to the Government of Eire at this juncture. The following points were made in discussion :—

(1) The supply of this equipment must be considered from the military point of view; namely, whether it would be more to our advantage to supply particular articles of equipment to Eire in order to induce better co-operation between the Eire forces and our troops in resisting a German invasion of Ireland, than to supply the same articles to our own units.

(2) There was some advantage in supplying Bren-carriers, since there would be a good case for sending men with them as instructors.

(3) The supply of searchlights must be further considered having regard inter alia to the need of Belfast for searchlights.

(4) I t was suggested that the supply of a certain number of steel helmets would have a useful psychological effect.

(5) There was clearly some risk in supplying equipment to Eire, and it might well be argued that the best way to induce Eire's co-operation was to withhold all supplies of equipment. Nevertheless the general view of the War Cabinet was that it was right to take the risk involved.

The War Cabinet—

Authorised the Secretary of State for War to supply equipment to Eire within the limits of the proposals set out in his Memorandum; which proposals should, generally speaking, be regarded as a maximum.
 
Top