But then Putin’s real battle would begin — as Russia and its Ukrainian proxies try to stabilize a country whose people largely detest them. If just 10 percent of Ukraine’s 40 million people decided to actively resist occupation, they would mount a powerful insurgency. Small bands of motivated fighters subverted America’s overwhelming military power in Iraq and Afghanistan.

Russia’s problems wouldn’t just be inside the borders of Ukraine. As Putin tried to digest what U.S. officials hope will be a Ukrainian “porcupine,” Russia’s economy would be squeezed tight by sanctions; its business and political leaders would become international pariahs; and much of the wealth Putin and his chums have accumulated would be frozen.

Ukraine might seem a triumphal victory for Putin at first, but it’s unlikely to have a happy ending. When leaders fight unnecessary “wars of choice” without a clear endgame, they often confront catastrophic unintended consequences. Think of Israeli Prime Minister Menachem Begin’s invasion of Lebanon in 1982, which helped create Hezbollah, or President George W. Bush’s invasion of Iraq in 2003, which destabilized the Middle East and made Iran a regional superpower. Putin would be the latest leader to join what historian Barbara Tuchman described as “The March of Folly.”