Russian President Vladimir Putin seems to have picked a bad time to try to restore the Russian empire. Collapsing energy prices are weakening the value of the ruble, causing inflation and depriving Putin of badly needed income.

We might expect his troubles to curb his appetite for aggression. Alas, it has not.

If anything, the former KGB operative is tightening the squeeze on Russia’s neighbors. Pro-Russia separatists in Ukraine appear to be readying a new offensive, possibly to take the port of Mariupol and establish a land corridor to the Russian-occupied province of Crimea. Vast convoys of tanks and trucks carrying howitzers and “Grad” rocket systems reportedly are moving through the separatist territory. NATO claims they are Russian. The alliance also continues to accuse Russia of sending combat troops into Ukraine.

Nordic countries are also under the gun. Russian bombers and submarines have penetrated the airspace and national waters of non-NATO countries Sweden and Finland. Another target of Russia’s ire, the Baltic States, are very much part of NATO. In September Russian agents crossed the border into Estonia. As smoke bombs and stun grenades exploded, they kidnapped an Estonian citizen on Estonian soil, bringing him to Russia on charges of espionage.

In both instances the message from Putin was clear: Your sovereignty partly belongs to Moscow, and you cannot depend on NATO to defend you.

Russia has been throwing its weight around as well in the South Caucasus. In 2008 it invaded and occupied two breakaway regions in Georgia, Abkhazia and South Ossetia. In November, Moscow and Abkhazia’s Russian-controlled government signed a treaty of alliance that appears to pave the way for its outright annexation by Russia. The same may also happen to South Ossetia.

So why is Putin continuing to act like a bully while his economic base is shrinking?

The most likely answer: because his economic base is shrinking! Nothing turns the minds of Russians away from their economic troubles more than a manufactured fear of an external threat, particularly from the U.S. Putin knows his soaring popularity rests in part on his image as the big man standing up to the West.

Another possible answer: because he can. The U.S. has signaled loud and clear that Russia’s so-called “near abroad” — the independent countries that once were part of the Soviet Union, like Ukraine, the Baltic States, Georgia and others — is a vast gray area up for grabs. Despite sanctions on Russia over Ukraine, the West more or less conceded that Ukraine is in Russia’s sphere of influence by not responding more forcefully to Russian aggression. Russia responds to economic sanctions with force, which tells Ukraine that it clearly matters a great deal more to Putin than it does to President Obama and the Europeans.

Finally, there is the desperation factor. Despite heavy investments already, Putin recently was forced to cancel the South Stream gas pipeline to Europe, partly for economic reasons but also because European resistance has only hardened in the face of his bullying. The Baltic States and other Europeans have started to see the danger of energy dependence on Russia. They are eagerly exploring ways to wean themselves off its oil and gas.

Putin may therefore be thinking he had better get all he can while he can. The window for using energy as a tool of geopolitical warfare may be closing.

Time is not on Putin’s side. Economic problems may limit his options in the long run, but in the short run he will try to take advantage of Western divisions to consolidate his gains. Germany always blows hot and cold on Putin, and he knows it. He’s likely expecting the West’s patience to wear thin. What better reason to cash in now on a strategic hand that will only weaken with time?

All the more reason the West must be vigilant and not let pressure on Putin subside.

Originally appeared in the Washington Times.