WW1 and 2 are pretty solid examples where military interventions have worked out just fine.
For most of europe, it's a traumatic experience that led to dozens of millions of dead young adults, entire cities firebombed and razed to the ground, areas shelled so hard that even today their access is forbidden.
But I'm sure it's much easier from a position of a country that never had a single war on its territory.
See: WWII