pre-WWI / WWII had its fair share of military alliances. None of those alliances were threatened and we know how that turned out.

Imho I think the threat of greater force does not prevent nations from taking drastic actions when pushed against a wall.

Civil unrest is caused by large unemployment especially of the young, which in turn leads to nationalistic and isolationist policies breeding bigotry and violence that are seized upon by demagogues. These are warning signs of something to come. The weird thing is they seem to be popping up all over both in eastern and western europe over the course of the last decade.

The US election in turn I think will definitely tilt the balance. From what i have seen it is not looking good on this side of the pond either.