The USA would defend them, as we defend every GD socialist state in Europe so that they can "notspend" on military, have huge socialist welfare states, and chide us for not having universal healthcare.
It really p's me off when they look down their noses at America for spending "too much" on the military and not enough on socialism. They COULDN'T BE socialist without America providing for their defense.
Mark Steyn once mentioned Vermont is an honorary member of the European Union demography wise. It will not be long for the country to be empty of people. The alternative would be the whole population consists of retirees (rich ones at 50, 60, 70) who worked in free market manners personally but hold socialist beliefs and decide to retire there and then vote in high taxations. Having got trust or off-shore accounts stacked they won’t pay any tax, it forces the tax on the rapidly shrinking working age people.
Either way they will go bankrupt in 20 years and will claw to Brussels, Ottawa, London, or horrors, Washington, for bailout.