In our time line, the Third Anglo-Afghan War ended after the successful defense of several frontier forts by units of the Indian Army. According to the treaty which restored the peace, Emir Amanullah (successor of Habibullah) lost his subsidy, but retained his throne. He also gained the right to an independent foreign policy, which the Afghan state at lost in the Second Anglo-Afghan War.
Correct.
Also, it's interesting that Britain didn't strip Afghanistan of any territory after this war. Ofc, if any territory was to be stripped from Afghanistan, it would be in the northern half of Afghanistan (since that's where most of Afghanistan's ethnic minorities live)--and Britain might have feared that Bolshevik influence would spread there if it separated these territories from Afghanistan.
The government of the Raj declined to exploit its defensive victories by going on the offensive against the forces of Amanullah. The reasons for this were
- the state of the Indian Army, the best units of which were still overseas
This would still be true in this TL.
- the restlessness of the Pashtun tribes on the Northwest Frontier
This would also still be true in this TL.
- the "strikes" by men of the Territorial Force serving in India, who, having volunteered to serve in the war against Germany, saw their employment in post-war conflicts as a breach of contract
This won't be a factor in this TL since Afghanistan is fighting in this TL's WWI.
Thus, we have 2 out of the same 3 factors going against us in this TL. Question is--is that enough for Afghanistan to still get a status quo ante bellum peace in terms of its borders in this TL?
Also, if so, might it encourage other Central Powers states to likewise demand peace based on the status quo ante bellum (when they are already losing the war, that is)?
Nonetheless, agents of the Raj did their best to undermine Amanullah. In 1929, these bore fruit in the overthrow of Amanullah by Nadir Shah.
Correct.
As far as either the Tajiks or the Hazara are concerned, I suspect that both the British and the Russians would be willing to subsidize any group that was willing to fight against a central government allied to the Central Powers. In other words, agents of the Entente powers would be more interested in distracting, punishing, and, if possible, overthrowing the monarch who had made common cause with their enemies than in laying the groundwork for any post-war settlement. (T.E. Lawrence, please call your answering service!)
That makes sense. That said, though, as I wrote above, Russia might not want an independent Tajik or Uzbek state since it could encourage Russia's Tajiks and Uzbeks to push for secession from Russia so that they could join their brethren across the border. The Hazara are probably a different matter, though. Ofc, the only way to reach the Hazara is to conquer a large part of Afghanistan from either the north or the south.