I assume M Marcel had family aboard one of the battlecruisers, poor sod.
The question is which ones, and how badly has that wrecked the Entente fleet in the area? The Med is now relegated to an afterthought, as all available resources will be heading East. The prior in this TL must think they're facing an absolute disaster. Little do they know it could be much worse.
War is terrifying.
On the other hand, they can have little doubt Uncle Sam is In on their side now.
Which might not be great news for the theater in the short run anyway; all of a sudden American exports to their forces might be in short supply, even repair parts might become scarce, as the US military grabs everything for themselves, and it will be a while before the same weapons in Yankee hands will be as effective, because the Americans are "green." And it will take some time to organize expeditionary forces.
But if they can just hold on with what they've got for a while, their forces will be greatly multiplied eventually; they shall surely come out ahead, the question is when. And to be sure, how much of the story of the Great War whereby European powers are beholden to arrogant Yanks is repeated.
OTL the answer to the latter question was, a whole hell of a lot. Here with FFO, it will be less so, but as you note they don't know how much worse off they could have been. During the Great War for the most part, at least with aircraft (maybe a lot less with ships and munitions) the Americans at least Bought European; it was a policy decision agreed to by Wilson not to attempt to develop American warplane designs, since the British and French state of the art was so highly developed and US resources would be better spent elsewhere. (American flying boat designs, by Curtiss IIRC, that is Glen Curtiss personally, were an exception, the British bought some of them which accelerated several makers in Britain designing their own on similar lines. But American aces of the Army Air Corps flew SPADs and Nieuports and so on; only the Curtiss JN "Jenny," a trainer, was mass produced for training and those stayed in America. Here it is pretty much the opposite for the French anyway, though Britain's factories are pouring out their makes the French arms industry is on hold, limited to whatever factories in Algeria can gear up to make at best. So the AdA and French naval aviation are at the mercy of American generals and admirals to the extent FDR gives them rein. It is a political balancing act for him, how many American made airframes continue to be sold, or donated, to foreign forces versus held back for the American forces to gain proficiency in and man themselves.
I suppose that the models France has ordered from Curtiss and others are specialized to French specifications and the US Army and Navy can be persuaded easily enough to let them go on through the pipeline, it is a question of how much new production gets diverted to US forces before new production plants can be built and go operational, that part is a time frame of a year or so and only that fast because of lavish use of resources, which America has of course.
The other looming question, which I expect will be settled as OTL but again these allies in Lebanon don't know it yet, is how much American effort will be made in the theater where we were actually attacked head on, in the Pacific which is mostly a sideshow for these Europeans though not entirely--the British are worried about Australia and New Zealand not to mention Hong Kong, Singapore, Malaysia, etc, the French are getting immediate bad news about Indochina and might worry about Polynesia as well.
Now the fact that the Japanese must reduce French colonial forces in Indochina must surely divert a lot of force they landed on the Philippines with OTL. Unfortunately I was shocked to learn some time ago (years ago, from various AH TL discussions) that it was decided way back in the earlier 1930s that the US could not cost-effectively project enough force to directly defend the Philippines, which I am not sure was a reasonable conclusion to draw. Certainly in the most cold-blooded sense, it is more efficient to put only token or theoretically zero forces in distant colonial holdings and then rely on Great Power deterrence to protect them; the hoisted flag is a paper barrier that if penetrated, triggers general war and then whoever can seize the islands without opposition easily enough has to face the entire USA coming after them with everything we can muster--later. A sort of early version of MAD. But the whole point of the US seizing the Philippines in the Spanish-American war was to provide bases for global power projection, that is anyway the main point and major justification put forth by the imperialists of the day--no one figured the Philippines would be some great economic resource in themselves. A parallel and somewhat less openly aggressive purpose was essentially the same reason the Spanish invested in taking the archipelago in the first place--it was a foot in the door for the China trade for Spain, and similarly holding Manila would be something of an asset for Americans asserting rights to trade in China.
Times change I guess. In the interim, Americans certainly did invest in enterprises in the Philippines and they were worth something directly. US government priorities changed with shifting politics; substantial domestic opposition to the initial wave of jingoist imperialism was present from the start and grew more pointed as US forces had to fight the Filipino insurrections for years thereafter, and eventually it became consensus the USA was going to belatedly spin the colony off as an independent nation, and it became a "Commonwealth" in the later interim, which might have had a lot to do with lowering the priority of defending directly. I still shake my head at the fatuousness; the decision to "civilize and Christianize" (per President McKinley) our "new caught half grown peoples half devil and half child" per Kipling's pro-imperialist and pro-Yankee encouraging words was no farther in the pasts of the 1941 defenders than 1978 is to us reading this today, and at that time it would have been insane to propose not defending them. Of course in 1941 sea and air power project was faster and more powerful, and Japan was much more relatively strong than in 1898, but I have little doubt that if US planners had felt a keen sense that losing the Philippines would be as bad as losing say Washington state, provision could have been made to blunt any landing attempts well enough to make the sustained defense feasible.
In fact I believe the US military either changed its mind again or had orders to attempt to do so, and that in the years immediately leading up to 1941 serious efforts had been made to beef up defenses and perhaps there was some optimism they could hold after all, despite a decade or so of neglect.
So coming back to ATL differences--OTL the Japanese could concentrate heavy force on taking the Philippines and hope to gain the upper hand there pretty fast in the wake of this heavy tackle, then route some of these forces on to the Dutch East Indies and their general OTL farflung dizzy success, especially since they counted on the US fleet being effectively removed from the Pacific for a considerable time,
(And it just now occurred to me--perhaps the ATL successes of the Pearl Harbor strike were somewhat greater than OTL. Most AH consideration seems to reach a consensus that they pretty much rolled sixes and fives in the OTL attack, that it would not be cost effective to divert even more strike force nor would extra waves of air strike be feasible, as while US air defenses were decimated what remained of them would be on ready alert for later strikes and effective, and that it was not feasible to do more damage to either the fleet or the vital repair facilities making Pearl an asset. But it could be that where they rolled a 4 or 5 OTL they rolled another 6 here and the damage is worse, that the carriers might have been caught in harbor for instance or that the channel might be blocked, or major infrastructure damage done beyond OTL. In short this PH could be worse, at least somewhat, than OTL. Not that I think it matters in the long run: I don't see how infrastructure damage could not be rapidly repaired or replaced at Pearl, and meanwhile the home ports of the fleet in the Pacific are in California and Washington state, not to mention what is based at the Panama Canal and what could come through it, which indeed Japan had schemes to strike at, but pretty far fetched and low hitting power schemes compared to the one-shot Pearl Harbor surprise strike).
So American capacity to respond immediately is no better than OTL and might conceivably be even less, but against this, the Japanese must divert their all-in OTL efforts to invest the Philippines, which they absolutely must attempt now, toward Indochina to a great extent. This has to give the American (and Commonwealth Filipino, who did well in their own right IIRC) defenders somewhat better odds, if perhaps still plainly doomed, at least they can slow down the invasion, delay the date of ultimate collapse of open warfare (insurgency never ended OTL, again largely to the credit of the Filipinos themselves) and decimate the IJA and perhaps IJN forces sent to do the job in initially lesser numbers due to the Indochina diversion (versus OTL I mean--in absolute terms, I suppose Indochina is the higher priority target and prize in itself, for its own resources and for the access it gives the Japanese to Thailand and thus projecting on to Burma and Malaysia--the point being that OTL they had this jump almost directly to British-claimed borders in hand already on Pearl Harbor Day, here they have to fight through whatever resistance Indochinese based force, French and domestically recruited colonial forces, can offer them. The Thai government might be aiding and abetting already, seeing the Japanese are sweeping all before them should tip the court over to the Axis side firmly, but they are pretty weak in themselves, the main relevance of Thai alignment with the Axis being the free hand they gave the Japanese to mobilize and take resources).
The additional resistance and diversion the need to fight their way to control of Indochina presents Japan, and possibility that it will slow them down in the Philippines too, in turn might buy very useful time for the colonial DEI forces to slow and perhaps even halt Japanese investment of their territory. OTL the Dutch colonists did resist stubbornly; if the initial blow is delayed and attenuated they might be more effective and aid might reach them soon enough to limit Japanese advances considerably.
I don't recall much discussion of DEI (some I think, regarding policy in either selling oil to Japan or not doing so per American embargo wishes, but not much else) which makes sense since they were an irrelevant backwater of the general war (except for that oil issue, or selling tropical resources such as rubber in general) until this dramatic moment when it all turns on a dime. But they are on the front now!
And of course OTL some rather infamous incidents of allied commanders being blamed for major bungling (MacArthur in the Philippines, what'shisname in Singapore) could, insofar as it was that and not just Monday morning quarterbacking, turn out otherwise based on essentially chance combined with delays and diversions of the attacks. MacArthur gets no delay versus OTL of course--in fact an OTL bit of random bad fortune for Japan (bad weather preventing an airstrike out of Taiwan exactly coinciding with the strike on Pearl that was planned) might go the other way, with Manila taken by surprise at the same moment Hawaii was per the war plan. But he will be facing less force I think--the only way it could be as great an invasion attempt as OTL would be if all the forces for the branch of ATL attack on Indochina are drawn either from forces in reserve in the Home Islands or are taken from OTL postings in China. In Singapore, and in Jakarta/Batavia, on the other hand, it might not eventually be a lesser force that approaches, but that approach must be delayed I think.
Even if the USN is even worse off due to Pearl being more decimated if that is possible, overall the Allies in the Pacific are better off, thanks to Japan having to fight for Indochina. That colony may be doomed to fall, but will cost Japan time and force to take it. Not to mention they are denied any resources they managed to accumulate from their de facto control much earlier OTL.
