Vladimir Putin took the oath of office to begin his third term as Russia's president on Monday, returning to the job after sitting out four years as prime minister. Outside the Kremlin, the streets were empty, as police hauled away opposition activists who were attempting to thwart the president's inauguration. Putin tried to defuse public anger with a series of decrees, vowing to eliminate waiting lists for nursery schools, and promising all Russians access to new housing every 15 years. But many observers warned of trouble ahead. Here, six concerning signs as Putin returns to the presidency:

1. No one showed up to cheer Putin
Putin's inauguration was an "impressive sight, full of tsarist pageantry," says Tom Parfitt at Britain's Telegraph. "But something was missing: The Russian people." The streets Putin's limousine traveled to reach the ceremony were silent, "blocked off by police trucks and devoid of human presence." Security personnel not only kept protesters away from the route, but supporters, too, which made it seem as if no one in Moscow felt there was anything to cheer about.

2. He promised freedom... and arrested the opposition
While Putin was on the dais, promising to uphold the freedom, security, and sovereignty of the Russian people, says Julia Ioffe at The New Yorker, people were being "arrested all over the city." The day before, riot police had stormed a cafe that was "a hub of opposition life," and snatched people off the streets for wearing white ribbons, "the symbol of the winter's peaceful anti-Kremlin protests." Four hundred people were thrown in jail, and scores were injured. 

3. Statisticians detected voter fraud in the March election
Putin won "a landslide victory in March," says Brian Jacobsmeyer at Physics Central, but a statistical analysis of the results uncovered "several questionable anomalies in the data that always seemed to support Putin and his party" — including clusters of polling stations where Putin's support was high and turnout exceeded 95 percent. "Putin's opponents have frequently accused him of unfair elections. Now, his opponents have one more piece of ammunition: Statistics."

4. Violent rebels are active... again
Just days before Putin returned to his old job, twin car bombs exploded near a police post in the republic of Dagestan. The explosions, which killed 13 people, served as "grisly reminders" that Putin will have to contend with more violence in his third term, says Jim Heintz of The Associated Press. In his previous terms, Putin largely succeeded in his vow to wipe out the Chechen insurgency, but "pacifying Dagestan is a tougher challenge." Dagestan is three times larger than Chechnya, with plenty of mountains where Islamic insurgents can hide, making it difficult for Russian forces to "unleash their overwhelming firepower."

5. Even China is more open to change than Putin
After 12 years in power, Putin "represents the specter of stagnation that haunts Russia," says Nicu Popescu at EU Observer. And he's hoping this is the beginning of two six-year terms. The contrast with "China's upcoming — and strictly choreographed — power transfer could hardly be starker." In the fall, China will replace the country's president, Hu Jintao, its premier, Wen Jiabao, and the rest of the nine-member Politburo Standing Committee. "Although China has the more authoritarian system, it is moving forward. The same cannot be said for Putin's Russia."

6. The U.S. media continues to demonize Putin
The relentless, and often unfair, demonizing of Putin in the American media "has made Putin's Russia toxic in Washington," says Stephen F. Cohen at Reuters. We hear he's a KGB thug and an autocrat — even though his power is far from absolute, which makes securing Russian cooperation difficult, just when the U.S. need Moscow's help in Afghanistan, North Korea, Iran, and the entire Middle East.