Vladimir Putin appeared to shed tears of joy the night he won back the presidency in March. After less than a week in office, he may be tempted to shed some in frustration.

Since his inauguration on Monday, the man whose 2000-2008 presidency was characterized by steely control and a cowed opposition has faced a wave of confrontations and misfortunes.

Opposition activists, energized by this winter's unprecedented wave of massive protest rallies and angered by Putin's March 4 re-election, which they claim was riddled with vote fraud, are showing new willingness to risk arrest and police beatings.

A corps of the most determined has occupied a Moscow square since Wednesday. Although small in number, the defiance is significant in a country where unauthorized rallies are routinely dispersed with force.

Putin has also taken hits on other fronts.

An airliner that is the pride of Russia's campaign to regain a foothold in the civilian aviation industry crashed Wednesday under mysterious circumstances in Indonesia. The next day, a project of even greater national significance — the 2014 Winter Olympics in Sochi, appeared vulnerable: Authorities said they had uncovered an elaborate and heavily armed plot to attack the games in the Black Sea resort.

Putin meanwhile baffled the world by announcing that he would not attend next week's Group of Eight summit in Camp David — a startling absence for a man who appears to relish the world spotlight.

Nor did the days leading up to the inauguration augur smooth sailing for at least the early part of Putin's new, six-year term. Tensions with the United States got a very public viewing when the military chief of staff threatened pre-emptive strikes if Washington moves ahead with a European missile-defense program. An inauguration eve protest attracted tens of thousands, well more than expected, and vivid scenes of police beating and dragging demonstrators played worldwide. Two car bombs in Dagestan killed 13 and wounded scores.

Putin's decision not to go to the G-8 summit — instead sending his predecessor and now prime minister Dmitry Medvedev — was explained as necessary for Putin to form his Cabinet. That raised eyebrow since Putin's return to the presidency had been all but certain since he announced his intention to run last September. Some observers suggested it gave Putin a convenient excuse to avoid a highly visible international forum where his tough line against dissent could come under criticism.

The harsh measures against protesters on the day before the inauguration and subsequent arrests at smaller protests in the following days were a harsh contrast to Russia's winter of discontent, during which demonstrators fastidiously stayed within the limits sanctioned by authorities and police in turn kept close watch but did not interfere.

But the opposition now is raising the stakes, even setting up a small round-the-clock demonstration in a Moscow square. That puts Putin in a bind. Either he invites international opprobrium with tough police action or risks allowing the opposition to expand its actions to something resembling the 2004 Orange Revolution tent-camp in Kiev. Putin denounced both the Orange Revolution and the similar Rose Revolution in Georgia — and allowing similar actions in Moscow could be seen as blinking first in a staring match.

One of Putin's strong suits against the opposition has been Russia's remarkable prosperity during his presidency and premiership. That has come mostly because of Russia's vast reserves of oil, gas and minerals, but the country has sought to move beyond its natural-resources economy to become a manufacturing power.

The new Superjet-100 regional airliner is a key piece of that strategy, and Russia is energetically seeking customers for it worldwide. The crash in Indonesia occurred during an Asian sales trip for the plane.

No cause has yet been determined, but either mechanical failure or pilot error would be a blow to Russia's image. If the plane itself was at fault, orders almost certainly would dry up. The plane's pilot was described as one of Russia's most experienced, and if his error caused the crash it would follow a run of Russian airline disasters blamed on poorly trained or inattentive crews.

The announcement of the foiled plot against the Sochi games hit at two of Putin's other traditional strong points.

Putin drove Russia's campaign to win the right to host the event and his success was not only a personal victory but a strong endorsement of Russia's aspirations to be seen as a country that is modern, welcoming — and secure. Sochi's location on the fringe of Russia's insurgency-plagued North Caucasus raised concerns about terrorist attacks, fears that were countered with Putin's strong record in the fight against Chechen rebels.

But the reported plot, blamed on insurgents, underlined that the militants, although less active than in recent years, have not been vanquished — a fact grimly underscored by the May 3 car bombs in Dagestan. A further embarrassment to the Kremlin could be seen in the claim that the plot was organized in Abkhazia, the Georgian separatist region adjacent to Sochi.

Putin, amid his difficult first week in office, did find time to reinforce his image as a strong leader beloved by salt-of-the-earth Russians. On Thursday, he made a well-publicized visit to a tank manufacturing plant in the scruffy city of Nizhny Tagil. The plant became a potent symbol for Putin in January, when a cadre of workers promised him on national television that they would come to Moscow, if needed, to battle the rising protest movement.