Ok. Let me use this as an opportunity to clarify this:
I just didnt like the way they wrote it. I have no problem with him not asking TNG people if there is a good reason not to. Maybe he is thinking back to "All good things.."
"I did ask them once and I got Crushers ship destroyed and 3 Enterprises "destroyed". (Although, wibbly wobbly timey wimey, they were not actually destroyed). He wont go that route again. It was ok to ask Starfleet for a ship since this appears to be a serious situation, even a national security threat, and thats what Starfleet ships and officers do.
He IS allowed to care more about his TNG colleagues. Or maybe they all have families and kids and Raffi doesnt. Asking the nuns is ok because warriors being bound to a cause is what they do anyway. If not bound to my cause, they would just end up working for some other cause, so why not?
But they didnt say all that. They had some lazy dumb lines. But let me say, since I think others here misunderstand....I am just saying I think they could have framed and explained it better. Not that their arent reasons to do what he has done. Anyone who disagrees is free to disagree.
I get all that, but the premise you seem to be working on is he asked these people to come help him out of goodwill. That is not the case. Two came along uninvited for their own reasons, one was paid (because this is how he makes a living) and another is honouring a code which he lives according to his customs. None are doing Picard any favours or there without motivations of their own.
Therefore an equivalence made with potentially asking his old crew fails because we are not given any reasons they would choose to be there of their own volition. They would be there out of loyalty to him, not self interest. They would feel obliged, these people all stand to gain.
American show made primarily by Americans for the last 50+ years.
About a Frenchman, played by an Englishman, living in France and going on an adventure in outer space having spent his life working for a distinctly socialist organisation and society of which he is still a citizen and really does not resemble the US at all.
In no way is the Federation an allegory about America specifically. Trek makes comments and raises questions about the world at times (sometimes more eloquently than others) but it is, and never has been, the case that the Federation is tied to representing any one real world nation. TOS episodes often commented on events like Vietnam (A Private Little War springs to mind) but that was on an episode by episode basis, not a broad strokes pairing. One could equally easily draw parallels with the old USSR as it's contemporary US in that regard, or have Starfleet represent NATO, or ask questions about British colonialism for that matter.
The people making the show said that. They wanted it to reflect on these times. Trump, Brexit, the refugee crisis, etc. The Federation is not the American system. It is not the EU either. Nor the UN. But if you want it to reflect the issues of our times, there are a lot of ways for them to do that, no matter what system of govt they say the Federation has.
I think Brexit and the EU serve as closer analogies here, the idea of a conglomerate of largely independent sovereign nations who can secede if they wish is much closer than that of a superstate, especially when the Romulan refugees are considered in the context of the Brexit campaign and the issues which fuelled it.
The decision to halt was (apparently) driven in no small part by the threat of secession by 14 races, which is clearly comparable to the European situation, although what the Synthetic attack says about 9/11 is another question especially given we do not yet know a great deal about exactly how it happened.