That's not the right measure. That's of "running NATO" itself ($2-$3B, for training missions etc), which is pocket change compared to the actual defense budget

That's not the right measure. That's of "running NATO" itself ($2-$3B, for training missions etc), which is pocket change compared to the actual defense budgets. And the US far, far dominates actual national defense spending, which is what matters for collective defense. It's the $700B the US spends on defense that backs the NATO defense commitment, not the couple billion spent on training missions.