Crimea is annexed. Russian forces are massed on Eastern Ukraine's borders. Rumors swirl about Russian designs on Moldova. The Baltic States await their time in the Russian crosshairs. Poland, the Czech Republic, Hungary and other former Soviet satellites shudder at the thought of again living under the Russian boot.

How should a resolute United States and Europe respond?

We must insist on a sovereign, independent and secure Ukraine respected by Russia. The 1994 Budapest Memorandum guaranteed the territorial integrity of Ukraine, including Crimea. Ukraine gave up its nuclear arsenal to Russia for this guarantee. Putin must pay a heavy price for violating it. If he doesn't, he will continue to feed on his neighbors.

Putin wants a restoration of the former Soviet/Russian sphere of influence. He said in 2005 that "the collapse of the Soviet Union was the biggest geo-political catastrophe of the 20th century." The 2008 invasion of Georgia erased any doubts about his ambitions.

Let's be clear. Neither the United States nor Europe wants a shooting war over Ukraine. Still, there are military options at NATO's disposal.

President Obama should reverse his unwise withdrawal from the missile defense agreement with Poland and the Czech Republic. We've dispatched fighter planes to the Baltic States. We can reassure our eastern and central NATO allies by planning joint military exercises. Putin needs to know that if he invades eastern Ukraine, NATO will answer the Ukrainian's inevitable request for arms. NATO's collective defense obligations to Latvia, Lithuania, Estonia and other former Soviet satellites must be reaffirmed.

However, we must realize that economic measures provide the West's real advantage and leverage over Russia. We can contain Putin's aggression by disrupting the Russian economy.

Putin will sacrifice Russia's economy in his delusional pursuit of restoring the "glory days" of the former Soviet Union. Russia maintains a First World military, but a Third World economy.

We have already taken steps. Limited sanctions have been imposed and some assets frozen. A small number of Russian oligarchs lost their ability to travel to the West. A $1 billion economic assistance package to Ukraine will soon be reality. Russia has been expelled from the G-8, which is fitting, since they should never have been admitted.

Putin still hasn't gotten the message. We can and should do more until he does.

We should build an "economic NATO" by implementing the pending Transatlantic Trade and Investment Partnership (TTIP - the US-EU free trade agreement). Congress can issue President Obama strict parameters for those talks through trade promotion authority. The United States and European Union control 45 percent of global GDP and 43 percent of global trade. This economic partnership will strengthen transatlantic military and security cooperation.

Putin's feeble Eurasian Economic Zone can't compete against an economically aligned transatlantic partnership. The TTIP agreement will facilitate American liquid natural gas (LNG) exports to Europe and Ukraine. This will lessen their dependence on Russian energy. President Obama should quickly approve the 24 pending applications for LNG export terminals. This will help Western economies and harm Russia's.

We could release some of the Strategic Petroleum Reserve (SPR). Some experts think this will drop the price of oil enough to cause further harm to Russia's finances. Russia depends on oil and gas exports to pay its bills. Putin won't be able to recover this lost energy revenue through increased vodka sales.

Military aggression in an age of global economic interdependence should cost an economically fragile aggressor state dearly. The oligarchs must experience pain and they'll make sure Putin does as well.

The West can use our economic power to insist that Russia give the same territorial and diplomatic respect to Ukraine, Georgia and other former Soviet Republics that it does to independent and non-aligned Finland.

We are faced with a serious threat. President Obama must stop minimizing Putin's aggression. Calling Russia a ". . . regional power" acting out of "weakness," provides no comfort to NATO allies in Eastern Europe. It could invite more Russian "regional" adventurism. Likewise, Secretary Kerry's statement regarding Putin's actions that "you just don't in the 21st century behave in 19th century fashion" shows a misunderstanding about the Russian history driving Putin.

Some ask "why should we care?"

Because the blood and treasure of America's greatest generation laid the foundation for the Post World War II freedom, prosperity and security of European democracies. Turning our backs on that remarkable achievement would be a real geo-political catastrophe constituting a supreme global emergency.

***

Congressman Dent is Vice Chairman of the Appropriations Committee's Subcommittee on State, Foreign Operations, and Related Programs.