(Mikhail Klimentyev/AFP/Getty Images)

MOSCOW - Two years ago today, Vladimir Putin returned to the Kremlin for his third term as Russia's president amid unprecedented street protests.

He had tolerated the protests during the presidential campaign, allowing them to march through Moscow and call for his ouster. But on the eve of his inauguration, he sent a strong message about what was to come.

As tens of thousands marched toward Bolotnaya Square near the Kremlin, fighting broke out between protesters and riot police. Exactly how it began remains in dispute, but by the end of the day, dozens of police helmets were bobbing in the river and hundreds had been arrested.

It was the end of Putin's patience and his first step towards making sure he would never be this vulnerable again. Over the two years since Putin returned to power, Russia has passed law after law, systematically restricting rights and at times seeking confrontation with the United States.

The scope of those restrictions is sweeping, including new fines for illegal public gatherings, pressure on non-governmental organizations, controls on access to the Internet, and even laws against insulting officials. Just this week, Putin signed a law imposing strict rules on bloggers that would make it harder for them to expose corruption and criticize officials.

Domestic critics have been targeted as well. Some have been forced out of key positions. Others have been silenced through corrupt courts. The rest of the opposition that confronted Putin in the streets has all but withered away.

Putin has also embraced a new muscular foreign policy. After Russia's recent annexation of Crimea, Putin delivered an address that sounded like a man getting a lot off his chest. He let loose about how Russia had been disrespected after the collapse of the Soviet Union and declared that it would never happen again.

Yet that aggressive policy was evident long before the crisis in Ukraine.

While his predecessor and protégé, current Prime Minister Dmitri Medvedev, pursued a "reset" in relations with the Obama administration, Putin turned back the clock even before his re-election.

Kremlin allies began harassing the U.S. Ambassador to Moscow. A few months later, Russia kicked out the U.S. Agency for International Development, jeopardizing social programs it ran throughout the country. A few months after that, ostensibly in response to a set of human rights sanctions passed by the United States, Russia cut off adoptions by Americans.

Last year, Putin again thumbed his nose at the White House, offering asylum to Edward Snowden, who is accused of leaking some of America's most sensitive surveillance secrets. Last month, Putin struck again, essentially kicking the U.S. government-funded Voice of America broadcasts out of Russia.

These moves likely have several explanations. Putin has sought to clamp down on dissent in Russia. He has, for example, targeted the few media outlets not already under the Kremlin's thumb and has sought to tame the Internet as well.

He may also be girding for leaner times ahead.

His popularity over the past decade was based largely on bringing stability and improved quality of life to the country. But much of that was due to rising energy prices, which fund much of the Russian budget.

With energy prices below what the Kremlin had expected, Putin has sought to bind the country with something else: the idea of Russian exceptionalism. It's marked by a return a fiercely independent and assertive Russia that leans on Orthodox Christian values, which the Kremlin and its allies portray as a beacon of morality facing a depraved West. Putin's Russia has, for example, clamped down on gay rights and signed laws against insulting religion. This week, a new law was passed to restrict the use of expletives in media and art.

These days, Putin may be feeling strong. He is riding high in the polls with an 82% approval rating following the Sochi Olympics and the annexation of Crimea, two extremely popular events in Russia. He also has a string of recent foreign policy notches in his belt.

Yet there are storm clouds on the horizon. Russia's economy is on the brink of recession. Western sanctions could make things even worse. The annexation of Crimea is expected to be costly as Russia invests in the under-developed region. Economic pain could quickly jeopardize his popularity. The instability Russia has allegedly sowed in Ukraine may prove hard to control. Russia's isolation from the world may start to sting.

Yet despite the uncertain future, the Kremlin has only ratcheted up its efforts. Russia may be at a crossroads, but Putin is not backing down.