It is obvious that Russia is conducting an invasion of Ukraine. This violates the 1994 Budapest Memorandum between Russia, Ukraine, the United States and Britain, in which each party agreed to respect the territorial integrity of Ukraine. Russia's claim that it is acting to protect the rights of Russian citizens in Ukraine is redolent of Hitler's claims that he was taking over Czechoslovakia and the free city of Danzig and attacking Poland to protect ethnic Germans. Russia has treaty rights in its naval base in Crimea, but it has gone much farther by taking over the whole peninsula; it is as if the United States, possessed of treaty rights in its base in Guantanamo, should send in military forces or auxiliaries into Cuba.

What is the United States prepared to do about this?

Not much, to judge from the brief remarks President Obama made in the White House press room Friday afternoon before hurrying over to speak, with evident relief, in the more welcoming venue of a Democratic fundraiser three blocks away at the Capital Hilton. “We are now deeply concerned by military movements taken by the Russian Federation within Ukraine,” Obama said at the White House. “The United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine.”

Pretty bland stuff. “Deeply concerned” rather than “gravely concerned”--a much stronger phrase in diplomatic argot. “The United States will stand,” not act or lead, “with the international community”--no mention of NATO or the European Union or fellow Budapest Memorandum signatory Britain--“in affirming that there will be costs,” affirming not assuring or promising, “for any military intervention in Ukraine.” Why add “any” if there is no doubt that there is intervention--excuse me, “military movements.”

Here are some suggestions of what the United States can do.

(1) Announce it will not only not attend the G-8 conference scheduled for Sochi but will move to expel Russia from the G-8. Russia doesn't belong in the G-8 anyway; the other members, the original G-7, have much larger economies with electoral democracies, free markets and the rule of law. Russia is deficient on each count.

(2) Move U.S. and other NATO military forces into Poland and other Eastern European NATO countries, particularly the Baltic republics. These nations have been extremely cooperative with the United States and have received the back of our hand in return.

(3) Move to set up the anti-ballistic missile facilities in Poland and the Czech Republic which Obama scuttled in 2009--on the anniversary of the Soviet invasion of Poland, when it was an ally of Nazi Germany, in 1939.

(4) Cut off Russian banks' access to U.S., European Union and Japanese banking facilities. Such moves squeezed Iran">Iran hard enough to get it to the bargaining table.

(5) Extend the list of Russians barred from the United States under the Magnitsky Act.

(6) Improve relations with Kazakstan, which has plenty of oil and long boundaries with both Russia and China. Don't worry overmuch about losing transit rights in other Central Asia republics and Russia, which are currently the sites for removal of military equipment from Afghanistan (because Pakistan is not making itself available). We can just leave it there for the time being.

(7) Investigate possible environmental damage caused by the Russian port of Kaliningrad, in that geographically disconnected part of Russia that was once the northern part of East Prussia. This sounds like a good task for the European Union.

Notably absent from this list is economic support for the government of Ukraine. That may well be desirable, but we should not be under any illusion that nation-building there is likely to be very successful any time soon.

The point is to cabin in the power of Russia, which has violated international norms in many directions, always with a view to cabining in the power of the United States. As Walter Russell Mead points out, Vladimir Putin has been playing a weak hand very aggressively and adeptly. But it is a weak hand, and the United States can weaken it further. They need to be squeezed and to see that they face bankruptcy. This is what Ronald Reagan did to the Soviet Union in the 1980s, particularly with his proposed anti-ballistic missile program, and the process was started by Jimmy Carter when he changed course after the Russian invasion of Afghanistan in December 1979.

Mead makes the point that the pundits who predicted until Saturday that Russia would not move into Ukraine are solipsists -- they assume that Putin sees the world as they do and will act as they would. That would indeed be nice. But Putin doesn't see the world they way we -- Obama supporters and Obama critics -- do. We are told we should not mourn the transformation of a unipolar world into a multipolar world. It's just selfish to want to see the United States as the world's leading power. But the alternative is between a unipolar world and a zeropolar world, in which aggressive actors like Putin's Russia, the mullahs' Iran and Syria's Assad can inflict tyranny, suffering and death to millions--and no one can stop or (preferably) deter them.