Members of NATO are meeting in Warsaw. They are dragging the U.S. back into its traditional role of guaranteeing the security of Europe, even though the continent is well able to defend itself.

The North Atlantic Treaty Organization was a necessary part of Containment, preventing the Soviet Union from dominating or conquering Western Europe. But after recovering from World War II the Europeans remained dependent on America.

NATO lost its raison d’etre once the Warsaw Pact disbanded and Soviet Union collapsed. Alliance officials eventually added “out of area” activities, that is, wars of choice irrelevant to Europe’s defense (Balkans, Libya, Mideast, Afghanistan). Such conflicts have wasted lives and resources with no benefit to Europe and America.

Still, enabling ethnic cleansing in Kosovo and spawning chaos in Libya were better than returning to a quasi-Cold War with Russia. Vladimir Putin is a nasty character, but upon taking office he appeared to bear the West little animus. However, the allies did their best to change that, expanding the alliance up to Russia’s borders, lawlessly dismembering historic Russian friend Serbia, backing Georgia in 2008 after it started the shooting, and supporting a street putsch against an elected Ukrainian president friendly to Moscow.

None of that justified the Putin government’s response, but Moscow’s ambitions have been limited. He shows no interest in conquering the NATO countries which so fear him; rather, he unsettled them by treating non-members Georgia and Ukraine rather like NATO treated Russia’s Belgrade friends.

In Georgia Moscow backed separatist-minded territories whose estrangement predated Tbilisi’s independence. In Ukraine he focused his ill attention on heavily ethnic-Russian areas.

He’s done nothing to the Baltic States: the fact that Moscow could overrun them doesn’t mean it has any rational reason to do so. Putin is no Hitler or Stalin, just a garden variety thug.

Which makes Europe’s behavior all the more disappointing. For decades the allies have been cutting military outlays. Collective defense spending by NATO’s European members continued to fall last year, when they devoted an anemic 1.45 percent of GDP to the military.

The Europeans enjoy around eight times the total GDP, devote more than three times as much to military spending, and have about three times the population of Russia. Yet they are demanding that America, with a smaller economy and population, defend them.

Many of today’s difficulties stem from NATO expansion, which treated the alliance like an international social club, bringing in countries of little strategic interest and no military value to America. For instance, Montenegro has been invited to join. With a military of precisely 2080 personnel, the best that can be said of Podgorica is that it is irrelevant to most everything geopolitically.

But Beke Kiria of Georgia’s Ministry of Defense recently asked, if Montenegro, why not Tbilisi? Luke Coffey of the Heritage Foundation and Daniel Kochis of the Davis Institute recently called on the alliance to “deepen its partnership with Ukraine” and keep the door open “for potential future Ukrainian membership.”

Including Tbilisi and Kiev would be reckless and dangerous, greatly increasing the risk of confrontation with a nuclear-armed power over minimal stakes. Of course, NATO’s security guarantee is supposed to deter Moscow. However, deterrence often has failed in Europe.

Russia’s interest in securing its borders is far greater than America’s and Europe’s interest in protecting Georgia’s and Ukraine’ borders. If deterrence failed, which NATO members would support war far from home and be prepared to escalate to nuclear weapons in order to safeguard … Georgia and Ukraine?

Washington should say no new members in NATO. But that should merely be the starting point at the meeting in Warsaw for a spirited debate about the alliance’s future.

As I ask on Forbes online: “Why, seven decades after the end of World War II, is Europe still helplessly dependent on America? Washington should announce that it plans to allow the Europeans to finally take over responsibility for their own security.”