Decline triggers nationalism and diversionary wars---it’s the only way to preserve his legitimacy.

You might reasonably conclude that the destruction of Russia's economy is great news for the United States of America. After all, won't it humble Vladimir Putin, forcing him to finally back out of his disastrous Ukraine invasion, soften his growing hostility toward Europe and the US, and generally ratchet down the brinksmanship and aggression that have made him so troublesome?

Actually, it's the opposite. The odds are that Russia's freefalling economy will make Putin even more aggressive, more unpredictable, and less willing to compromise. The weaker that Russia becomes, the more dangerous it will get, and that's terrible news for everyone, including the US.

It is precisely because the cratering economy is weakening Putin that it will force him to bolster his rule, which he will almost certainly do by drumming up nationalism, foreign confrontations, and state propaganda. Russia, already hostile and isolated, is likely to become even more so, worsening both its behavior abroad and the already-significant economic suffering of regular Russians. The country's propaganda bubble will further seal off Russians from the outside world, telling them that Russia's decline is the fault of Western aggression that they must rally against.

In all, this effect is starting to look something like the North Koreaification of Russia. That does not mean that Russia is about to become or will ever be as isolated, hostile, or aggressive as North Korea, but it only has to edge a little bit in that direction to bring terrible consequences for the world and for Russians themselves.

Putin's handling of Russia's last downturn is a very bad sign for how he'll deal with this one

We don't have to guess at how Putin will respond to a weakening economy: we already know the answer from how he dealt with the economic downturn that began for Russia in 2008, and hit home for Putin in 2012 when Russians protested his sham reelection.

Before then, Putin had certainly been a provocateur, but nothing like what he is now. He based his power and popularity on Russia's economic growth, which was enough. But after 2012, Putin shifted strategies, focusing on stirring up old-school anti-Western paranoia and imperial-style Russian nationalism.

That meant ginning up conflict with the US, for example by banning American families from adopting Russian orphans, and seizing on geopolitical crises such as Syria as an opportunity to present Russia as a great power opposed to nefarious Western imperialism. It also meant cracking down on free speech and civil rights at home, cracking down on everyone from journalists to gay and lesbian people, while ratcheting up nationalistic propaganda in the media. And, ultimately, it meant invading Ukraine, which Putin presented as a humanitarian intervention to save fellow Russian-speakers from evil Western fascism.

All of this worked: it distracted Russians from the sinking economy, focusing them instead on perceived enemies at home and abroad: Ukraine, the West, Russian liberals, Russian gays and lesbians. In fact, Putin's approval rating even rose, to a meteoric high of over 80 percent. But the danger is that Putin became trapped in the logic of his own propaganda, which is a big part of why he invaded Ukraine again, this time in eastern Ukraine.

The worse Russia's economy gets, the more Putin will need to escalate hostility abroad

As the economy sinks, Putin will only become more reliant on these sorts of shenanigans he's used previously to stay in power. He's not just worried about his popularity, after all, but his very legitimacy as the head of state; the 2012 election showed him that Russians could turn against him.

Putin has little choice, then, but to seek legitimacy by stirring up more crises abroad, positioning himself as a nationalist hero leading the brave Russian state in a hostile world. But the only way he can maintain that image at home is if his soft conflict with the West continues. Putin can't deescalate tensions in Ukraine and more broadly in Europe because those tensions are just about all he has left.

More broadly, the obvious move here is for Putin is to blame his country's falling economy on American and European imperialism. By playing up the role of outside hostility in Russia's economic crisis, Putin would shift the blame and, just as important, promote the idea that Russians have to come together and endure the downturn as a matter of national mission against a foreign enemy.

This is part of why Putin has spent much of 2014 comparing the pro-Western Ukrainian government to Nazis and talking about World War Two. The memory of Nazi Germany's 1941 invasion is still palpable in Russia. By hitting on the memory of those years of hardship and struggle, and raising subtle and not-so-subtle comparisons to the international tensions today, Putin is trying to persuade Russians that, the worse things get, the more that they should support him and his government.

That's working, but the worse Russia's economy gets, the more that Putin will have to exacerbate tensions with the West in order to justify blaming it all on foreign conflict and enemies.

Putin has every reason to keep the conflict in Ukraine going, or even make it worse

It's not just that Putin needs to maintain tension and conflict in order to maintain his self-made image as a tough-guy nationalist leader holding strong against a hostile West. Even his short-term strategy in Ukraine points to further escalation.

Putin can't simply withdraw from Ukraine, which would be a public humiliation. He's currently too invested in a losing situation to cut his losses. Mark Galeotti, a New York University scholar who studies Russia, points out that Putin might conclude that his best bet is to escalate even further, sending more troops, to try to force a better deal.

After all, Putin cares more about Ukraine than the West does — this is true — and at some point the very weak Ukrainian government may concede defeat and allow Putin more favorable peace terms. The more that Putin's economy suffers, the more likely he is to try some dangerous gambit like that to ease the cost of sanctions.