Stability doesn't mean statis. The USA has been remarkably resilient to those minor shocks you listed. It continues to be the most politically stable of all the countries that actually count for anything in international affairs.
If some catastrophic event is required to define instability, then by definition any country will be stable right until one second before catastrophe. This may work fine for certain analyses, but for predicting if or when that event may happen it is useless.
You're saying "nothing bad will happen because nothing bad has happened so far". There's a first time for everything.
If those are "minor" shocks then is it only outright war that counts as instability for you?
If so then what countries in Europe (sans the Balkans) or East Asia do you think are less politically stable than the US?