I think states which pursue this strategy will find that with an aggressive enemy "just buy a competent military" is not something that you can accomplish in less than a generation.

How many European nations could "buy weapons" and then pull off a minor shooting war against a local tinpot dictator whose military budget would be lost in Toyota's R&D expenditures? (e.g. Save Kosovo... without calling the US.)

I think the answer to the rhetorical question is "exactly one", although I can name two others which would actually have the capability of showing up in time to drop a bomb or two, to no strategic effect. The others are universally incapable of even getting to the theatre.

And if Russia decided to get frisky and send in the tanks? Most nations in Europe would fold about as fast as Georgia did -- their sole means of defense is not being "acceptable, if regrettable, losses" in Washington.