BRUSSELS — After the collapse of the Soviet Union, some asked whether NATO had any real reason to exist. But Russia’s invasion of Ukraine gave new urgency to NATO as a defensive alliance aimed at deterring a bellicose Moscow.
Now, at its annual summit meeting this week in Madrid, leaders of the 30 members of NATO are set to agree on the most significant overhaul of the alliance’s defenses since the Cold War.
The war in Ukraine has radically altered the security calculus in Europe,…
