Damn. I knew there were going to be nukes at play, but I thought it would just be a few of the key cities like Baghdad, Cairo, and Riyadh with maybe the occasional tactical nuke. Here, Israel and the Roman Alliance went full Judgement Day on the UAR and completely destroyed it as a country. Sadly, I don't think there's going to be any effort to rehabiliate the Arab people with the RA and Israel looking for a series of partitions that Sykes-Picot look lenient. So most Arabs will still hate Jews which will reinforce the stereotype of all Arabs being Nazis and making them the most hated race in modern times. Even with the Troubles making a more racially progressive America, I don't think anyone is going to get a second glance when being racist towards Arabs, with any positive depictions in Hollywood probably being seen as sympathetic towards Neo-Nazism.
As horrific as Samson is, many will justify it as being done in the prevention of a Third Holocaust, which can be a pretty strong argument. The real kicker is De Gaulle's decision to nuke the desert Algerians which was completely overproportional and was done for sole imperialistic purposes rather than for a moral cause. I predict that this is going to cause a strong break in relations between France and the Anglo world with America and Britain distancing itself from France as radical imperials while De Gaulle uses this as justification for having France be an independent Great Power that is more aligned towards the Roman Alliance. I can't see the French Left taking this easy and there has got to be mass protests and riots in the nation. What complicates this is that when word gets out that Aflaq had Nazis in his inner circle, it's going to kill any opposition to De Gaulle as being seen as pro-Nazi. French politics is going to be very interesting moving forward.
On Britain's side, I think this is going to force them away from Italy with the sentiment of Mussolini as their southern friend being killed, possibly being the end of Mosley's Fascists. This will make Britain deepen their special relationship with America, and I think the imperialism of the future peace agreement will force even the Conservatives to shift towards more of a Commonwealth than holding onto the Empire tightly, though several territories like Hong Kong, El Salvador, and the Caribbean islands may still remain.
On the topic of Italy's involvement with Ethiopia, I don't think it's going to cause the collapse of the Fascist movement. As it's been stressed before, Fascism here works on a technical level since Italy owns the Mediterranean as their lake, is rising as a superpower equal to America and the Soviets, won the second world war and expanded the empire greatly, and they are seen as morally righteous for saving the Jews. While Fascist Italy is undoubtedly no paradise with many cruelties domestically, Mussolini and his successor can always point to the glories of New Rome. Ethiopia can't be Italy's Afghanistan because while the Soviets were either in deadlock or losing the Cold War, Italy has seen win after win while at the moment they have at least cordial relations with the West and can always point to the USSR as the greater evil. So I don't think the Ethiopian insurgency will cause the Empire to collapse since Italy won't be held back by moralities and inflict many atrocities to keep the population in line. I do think that it will cause the regime to weaken, especially with the fall of the USSR preventing any more close relations with the West along with potential economic troubles. I believe that in the future Fascist Italy will still exist in a PRC style, or a "Democracy" will rise up with the Fascists being the dominant party for many years like the PRI in Mexico.
Overall great story and I can't wait to nominate this for the Turtledoves.