What to Know About NATO, Putin and Article 5

If Russia’s invasion of Ukraine was supposed to weaken NATO and stop its eastward expansion — one rationalization offered by President Vladimir Putin — it seems to have backfired. Rather than exploit tensions within the alliance, Russia’s war seemingly strengthened it, with Finland and Sweden, two close neighbors of Russia, seeking to join. The countries that make up NATO have not fired a shot as part of the Russia-Ukraine conflict. But the alliance came close to being pulled in when a Russian-made rocket was reported to have landed in Poland, a former Soviet ally turned NATO member. While it was immediately not clear whether the rocket was fired by Russians in offense or Ukrainians in defense, the event raised questions about sections of the NATO treaty called Article 4 and 5.

Founded in 1949 to protect Europe against Soviet attack during the Cold War, the North Atlantic Treaty Organization has come to represent a fundamental partnership between North America and Europe based on shared political and economic values. Membership has grown to 30 nations from 12.