Potential dramatic happening soon

There was no "world police" prior to WW2.

You're quite wrong. Take a gander at this piece from F. A. Voigt in Unto Caesar (1938):

Monstrous proposals, like the proposal to create an international air force that would emerge—from some Alpine stronghold, presumably—and bomb the cities of the alleged aggressor, found a considerable following in the post-war years. Such inhuman phantasmagoria had an affinity with the secular religions of the European continent. Indeed, English militant pacifism had something in common with the Marxian dreams of a universal realm of peace, justice and well-being. As we have seen, the Kingdom of Heaven on Earth is inseparable from its own opposite. It can only come about by violence. The threat of universal war as a means of establishing universal peace is a peculiarly English conception that has crystallized in the doctrine of “sanctions.” This doctrine is analogous to the doctrine of the proletarian dictatorship which would establish social peace by making class-war permanent and universal. “Sanctions” are the counterpart of the revolutionary terror—the purpose of either is peace, but the effect of both is the consolidation, through war or the threat of war (whether between classes or nations), of power in the hands of those hold it.

[…]

To erect the “punishment of the aggressor” into a general system would be to concentrate immense power into a few hands and establish an abominable and universal tyranny. In nothing is the evil inherent in universal systems of enforced morality more evident than in the doctrine of “sanctions.”

For 'international air force' read 'Nuclear annihilation'. Voigt was an old-line British imperialist. But by the 30's he starts to show some pangs of guilt.

You're right that the world was multipolar in the 1930's — there were two poles: Anglo-American hegemony and a handful of loosely allied independent countries who weren't getting with the program. It was much more multipolar in the 1830s, to say nothing of the 1730s.

You can be sure that this 'universal peace liberation' line of thought was circulating through the great war period, too. Take a look at this bit of rambling from Lord Grey in his memoirs:

Nothing but the defeat of Germany can make a satisfactory end to this war and secure future peace…

We must, however, be careful in stating our determination to continue the war to make it clear that our object is not to force, but to support our Allies. Increasing mischief is being made between us and our Allies by German propaganda. This propaganda represents the war as one of rivalry between Great Britain and Germany; it insinuates that France, Russia and Belgium could have satisfactory terms of peace now, and that they are continuing the war in the interest of Great Britain to effect the ruin of Germany, which is not necessary for the safety of the Allies, but which alone will satisfy Great Britain.

It is just possible that this insidious misrepresentation, false though it be, may create in France, Russia, Italy and Belgium a dangerous peace movement—a movement positively unfriendly to us.

It would be well if we could all, Ministers and Press alike, strike one note, that of determination to help the Allies who have suffered the most grievous wrong, to secure the liberation of their territory, reparation for wrong done, and the advantages necessary for their future security. We should emphasize the impossibility and disgrace of thinking of peace till the Allies are secure, but should let it be understood that it is for them whose territory is occupied by the enemy, whose population has been, and is being, so grossly ill-treated, rather than for us, to say when it is opportune to speak of peace. Till that time comes, we use all our efforts and make every sacrifice to defeat the enemy in the common cause, and have no other thought but this.

Just take a second to dwell on the phrase 'dangerous peace movement'. 'We're not fighting for our hegemony, we're fighting for our allies. If they want to make peace, that's fine — just, as long as it's peace on our terms. Until then, there must be no peace. After all, we must secure reparations and liberation for them'.

Keep in mind, that these two sources are Pro-britain. Voigt was starting to see the cracks in the seams, but couldn't reconcile it with the vision of imperialism that he grew up in. Grey didn't even realize he was struggling with doubt, he just talks in circles.

At any rate, you can be assured that this thinking is quite old, and — coincidentally or not — correlated with the advent of total war and the bloodiest conflicts in human history. The intent is peace, but the effect is war. At least so I think.

It's interests are quite abstract and ideological, though — unless there's some monetary benefit to supporting insurgents in Libya and Syria. When Obama said Assad must go, was he being informed by a projection of increased oil revenue, or something?

In fact, the US is openly sworn to the spread of democracy and peace, and quite routinely supports liberation efforts whose financial incentive is nil, seeing as the effect is typically to set certain parts of the world on fire.

The US was absolutely world policing in WW2 (E.g.), in fact, their policy for it was formalized before they had even entered it.

Conflicts before that were going to happen would absolutely not have happened with the certainty that US interference gave it. Would Libyan insurgents have tried to topple Gaddiffi, if the US hadn't gave them a wink, wink, nudge, nudge?

Without a 'world police', nations with strong militaries will indeed have free reign to do what they want to their weaker neightbours. They already do — unless you were to think that the US, and by extension, it's allies, — are 'weak'.

Any strong nation could take up that position when it's gone. This isn't really worth the effort, though (it costs a lot of money for very little return — at least the British were profiting off of their colonies), and so is only pursued if the nation is also possessed by an ideological zeal — for instance, to support World-wide revolution, or perhaps quasi-religious obsession with spreading freedom and democracy. Classical international law didn't persist for hundreds of years for nothing.

We run at a surplus actually. Christmas bonuses were in the 5 figures