After Donald Trump's four-year flirtation with Russian President Vladimir Putin, Joe Biden is setting a new, colder tone -- unhesitant criticism, despite openness on arms control.
Biden in his first week has already taken Moscow to task on its arrest of opposition leader Alexei Navalny as well as its alleged hacking, election interference and bounties on US troops -- but also quickly moved to extend New START, the Cold War-era powers' last remaining nuclear reduction treaty.
Biden's approach is nearly the mirror opposite of that of Trump, who spoke fondly of Putin but whose administration tore up arms agreements.
The White House last week announced a five-year extension of New START but simultaneously said US intelligence would launch a volley of investigations into Russia -- including whether it was behind the massive SolarWinds hack which Trump, contradicting experts, said could have been the work of his nemesis China.
The new secretary of state, Antony Blinken, at his first news conference hailed Navalny, the persistent critic of Putin whose poisoning and then arrest on his return to Moscow have inspired thousands to take to the streets.
"It remains striking to me how concerned, and maybe even scared, the Russian government seems to be of one man -- Mr. Navalny," Blinken said Wednesday -- a far cry from Trump in 2016 taking delight on how Putin was had been "very nice to me."
US experts on Russia expected Biden's opening moves to reflect a longer-term hard line -- although they also doubted how much Putin was swayed by any US president, especially as he faces protests.
Ian Bremmer, president of the Eurasia group, said the US-Russia relationship "is probably the worst it's been since the Soviet Union's collapse."
"The Biden administration is more unified on its tough message and more unified with allies, and that on the margins will put a little bit more pressure on Putin," he said.
US intelligence found that Russia meddled in the 2016 election to support Trump, who notoriously appeared to take Putin's denials at face value during a 2018 summit in Helsinki.
But Bremmer noted that despite Trump's friendliness toward Putin, everyone around the tycoon opposed warming relations with Russia including his cabinet, Republicans in Congress and most conservative-oriented media.
"There was no ability for Trump to actually improve the reality of relations between US and Russia and it never happened," Bremmer said.
Trump, with his fondness for authoritarian leaders, was unusually solicitous of Putin but he was not alone in starting his term by seeking better ties.
Barack Obama spoke of a "reset" of ties, following Russia's 2008 war with Georgia's pro-Western government, while George W. Bush said after his first meeting with the former KGB agent: "I was able to get a sense of his soul."
Biden has chosen aides known for their hawkishness on Russia -- notably Victoria Nuland, the nominee to be the number three at the State Department, who joined protesters in Ukraine in solidarity as they ousted the Moscow-aligned president in 2014.
William Pomeranz, deputy director of the Kennan Institute at the Woodrow Wilson International Center for Scholars, said that extending New START was a "low-hanging fruit" -- it was due to expire within days and Trump's efforts to expand the treaty to China made no headway.
But he said that Putin's actions, including blaming the United States for protests in support of Navalny, showed he was not looking for common ground with the United States.
"It takes two to improve relations and Vladimir Putin has not given any indication that he wants to change the tenor of US-Russia relations," Pomeranz said.
Pomeranz expected the Biden administration to end the "personalized and ad hoc" policy of Trump.
"I think the lesson from the Trump administration is that if the United States doesn't hold Russia accountable for its actions, it will not be deterred -- it will take those opportunities and expand them," he said.
"What we have now is the return of a more professional but nevertheless hardline administration that will not give Russia the benefit of the doubt."