MOSCOW — Adding to fears that the Kremlin aims to stifle dissent, Russians now live under a new law expanding the definition of treason so broadly that critics say it could be used to call anyone who bucks the government a traitor.
The law took effect Wednesday, two days after President Vladimir Putin told his human rights advisory council that he was ready to review it.
His spokesman Dmitry Peskov told Russian news agencies on Wednesday that Putin would be willing to review the treason law if its implementation reveals ‘‘some problems or aspects restricting rights and freedoms.’’
But what Putin might consider a problem is unclear. His opponents say a series of measures enacted since he returned to the Kremlin in May for a third term show he is determined to intimidate and suppress dissidents.
One recent measure imposes a huge increase in potential fines for participants in unauthorized demonstrations. Another requires nongovernmental organizations to register as foreign agents if they both receive money from abroad and engage in political activity. And another gives sweeping power to authorities to ban websites under a procedure critics denounce as opaque.
After fraud-tainted parliamentary elections last December, an unprecedented wave of protest arose, with some demonstrations attracting as many as 100,000 people. Putin still won the March presidential election handily, but the protests boldly challenged his image as the strongman Russia needs to achieve stability and prosperity.
Under the new law, anyone who without authorization possesses information deemed a state secret — whether a politician, a journalist, an environmentalist, or a union leader — could potentially be jailed for up to 20 years for espionage.
While the previous law described high treason as espionage or other assistance to a foreign state that damages Russia’s external security, the new legislation expands the definition by dropping the word ‘‘external.’’ Activities that fall under it include providing help or advice to a foreign state or giving information to an international or foreign organization.
The definition is so broad that rights advocates say it could be used as a driftnet to sweep up all inconvenient figures.
‘‘I believe this law is very dangerous,’’ said human rights council member Liliya Shibanova, according to the ITAR-Tass news agency. Shibanova also heads Golos, Russia’s only independent elections watchdog group.
‘‘If, for example, I pass on information about alleged poll violations to a foreign journalist, this could be considered espionage,’’ she said.
‘‘It’s very broad and it’s very dangerous,’’ said Rachel Denber, deputy director of Human Rights Watch’s Europe and Central Asia division.
She said it’s not clear yet how vigorously Russian authorities will enforce the bill, but says it recreates a ‘‘sense of paranoia and suspicion and uneasiness about foreigners.’’
Putin has repeatedly dismissed opposition leaders as pawns of the West and once accused US Secretary of State Hillary Rodham Clinton of instigating protests to weaken Russia. The law, which was drafted by the Federal Security Service, the primary KGB successor agency known by its Russian acronym FSB, also introduced a punishment of up to eight years for simply getting hold of state secrets illegally even if they are not placed in foreign hands.
The FSB said in a statement run by ITAR-Tass news agency that the new clause better protects confidential information. It said the previous law, which dated back to the 1960s, failed to provide efficient deterrence against foreign spies.
‘‘Tactics and methods of foreign special services have changed, becoming more subtle and disguised as legitimate actions,’’ the spy agency said. ‘‘Claims about a possible twist of spy mania in connection with the law’s passage are ungrounded and based exclusively on emotions.’’
Tamara Morshchakova, a former Constitutional Court judge, told a presidential rights council meeting Monday that the new law is so broad the FSB no longer needs to provide proof that a suspect inflicted actual damage to the nation’s security.
‘‘Their goal was simple: We have few traitors, it’s difficult to prove their guilt, so it’s necessary to expand it,’’ Morshchakova said. ‘‘Now they don’t have to prove it any more. An opinion of law enforcement agencies would suffice.’’
The revised treason bill first came up in 2008, under then-President Dmitry Medvedev, who quickly shelved the bill after an outburst of public criticism.
Medvedev, now prime minister, was seen as more reform- and compromise-inclined than Putin and initially raised tepid hopes that Russia would turn away from the domineering policies of Putin’s first two terms as president. But Medvedev was a comparatively weak leader and stepped aside to allow Putin to run for another term.