You have to consider how much it felt like progress for Europe to become less militaristic. The continent had been obliterated by war and then divided and filled with tanks during the cold war. For Europe, reducing military spending was seen as a welcome step away from the internal conflicts of the past. This is changing now, and while America may see this as a victory I find it hard to welcome headlines like “Germany to massively increase tank production” for all the negative historical echos.
I’d also be very surprised if US military expenditure decreased by a single cent as a result of increased spending by other NATO countries.
These are fair points and I get it, but the world of today is very different than the world of the early to mid 1900s. Lack of military is far from the only thing keeping Germany from attacking other European countries now. I feel reasonably confident that no matter how many tanks Germany builds, they won’t go rolling into France in my lifetime. What they may do is repel Russia (though even then, I am skeptical that any major nation will attack a NATO country.)
I’d also be very surprised if US military expenditure decreased by a single cent as a result of increased spending by other NATO countries.