One of President Vladimir Putin’s goals for his invasion of Ukraine was to upend the balance of military power in Europe. Mr. Putin has achieved that goal, but surely not in the way he intended.
Instead of strengthening Russia and pushing NATO back to its Soviet-era frontiers, Mr. Putin now faces an alliance more united than at any other time since the disintegration of the Soviet Union, more determined to curb Russian revanchism and — with two major Northern European powers, Sweden and Finland, seeking membership — more formidable as an adversary. At the NATO summit in Madrid this week, the road now looks clear for the alliance to expand and encompass those two nations.
But in the rush to counter Mr. Putin and deter Russia from such aggression, the United States and its allies should not lose sight of the fateful choices they are about to make. They should take a clear and sober look at what they really want their alliance to be and what inviting Sweden and Finland entails. The heart of the alliance, Article 5, pledges every member to come to the defense of any member.
Answering some of the alliance’s existential questions also means convincing Americans that an expanded NATO is worth the potential costs. A poll from the Eurasia Group Foundation published in the wake of the end of the war in Afghanistan found the American public about evenly split about going to war for an existing NATO member.
Some expansions of NATO have come after serious debate in the U.S. Senate, with lawmakers raising valid concerns about the alliance. For instance: whether its requirement for unanimous consent has become unwieldy with now dozens of nations as voting members. Other concerns include the cost of U.S. military deployments, although, unlike the accession of smaller nations with tiny armies, Sweden and Finland would significantly increase NATO’s firepower. Other critics have wondered whether Article 5 of the NATO treaty, which declares an act of aggression against one…