Although I upvoted you, it's a variable that you control only to some extent. At some point you will have an enemy that is irrational, power-hungry and unwilling to negotiate.
This is true, which is why Europe is now back to spending on defense, but you also have to consider the incentives here. Power-hungry people can use threats only if their populace can be whipped up by them. The fact that its largely impossible to gain approval in France by threatening Germany with invasion is a large part in why peace in Europe is so persistent.
This is hardly historically true. What actually happened was Europe was devastated by two industrial total wars which is what led to this circumstance.
And then in the aftermath faced a Russia which promptly seized a whole bunch of Baltic states.
Or to put it another way: up till this year Canada was not planning it's strategic defence strategy with the US as a possible threat actor.