(Bloomberg) -- Want to receive this post in your inbox every day? Sign up for the Balance of Power newsletter, and follow Bloomberg Politics on Twitter and Facebook for more.Donald Trump and Vladimir Putin sat down today for their first serious interaction in 12 months. The U.S. president marked the occasion with humor.At the start of their meeting at the Group of 20 summit in Japan, Trump was asked by reporters if he’d warn the Russian president not to meddle in the 2020 U.S. election. Turning to Putin, he wagged his finger and said: “Don't meddle in the election.”Trump then smiled. After a translation delay, Putin duly chuckled.Trump later said it had been a “very good meeting.” Still, the fact they are even talking is no laughing matter.After their last one-on-one in Helsinki, U.S. lawmakers blasted Trump for siding with Putin over the question of Russian interference in the 2016 presidential vote. Trump had to walk his comments back. Tensions over Crimea and the poisoning of a former Russian spy in the U.K. then overshadowed relations.Trump’s decision to see Putin now reflects his view U.S. voters have moved on. It arguably boosted Putin’s status, even as acting Defense Secretary Mark Esper said Russia “interferes in the sovereign democratic processes of other countries.”For the Kremlin leader, Trump's jest is a small price to pay for some validation.Global Headlines The big question | Trump mixed tariff threats with optimism ahead of his meeting tomorrow with Chinese President Xi Jinping — a chat that may determine whether they can secure a truce in their trade war. The U.S. president said there was a “good chance” of doing “something” with China, but also said he had not pledged to avoid further tariffs on Beijing for six months.Read about the chatter at the G-20 over German Chancellor Angela Merkel’s healthDemocratic clash | Kamala Harris staked her claim to top-tier status in the Democratic primaries with a searing indictment of front-runner Joe Biden on race, putting the former vice president on the defensive and puncturing the aura of inevitability he’d sought to cultivate. The confrontation at last night’s Democratic debate pitted the 54-year-old daughter of Jamaican and Indian immigrants against a 76-year-old white man for fondly recalling his civil relationships with segregationist senators in the 1970s and 1980s.Click here for more key takeaways from the debate.Standing apart | U.S. Chief Justice John Roberts has often said the Supreme Court isn’t a partisan institution. Confronted with two of the court’s most explicitly political cases in years, the Republican-appointed Roberts underscored his independence by joining the court’s four liberals to at least delay Trump’s bid to put a citizenship question on the 2020 census.Rebel May? | Theresa May is stepping down as U.K. prime minister in July but is already hinting she will use her newfound freedom to cause problems for her successor. The front-runner to replace May, Boris Johnson, hasn’t ruled out suspending parliament to force through a no-deal Brexit — and she won’t rule out rebelling against his government to stop him.Backing Barnier | Acceptance is growing for the European Union’s chief Brexit negotiator Michel Barnier to be appointed the bloc’s most senior official, even as his natural political allies remain unconvinced. Barnier is emerging as a compromise candidate to become president of the European Commission despite not saying publicly that he wants the job, Ian Wishart and Ben Sills report. The EU’s 28 leaders hold their third summit to discuss how to fill top posts on Sunday.What to WatchIsrael and Hamas reached a truce today that would halt attacks against Israeli farmland in return for measures to ease the economic blockade on Gaza, Israeli Army Radio reported. The Senate is set to vote on a bill requiring Trump to seek congressional approval for any military action in Iran — one of the few measures considered by the Republican-led chamber to curtail his war-making ability. Ethiopian security forces detained 255 people following attacks over the weekend in which five government officials died.And finally…Chernobyl has become a tourist hotspot following the success of HBO’s TV docudrama about the world’s worst nuclear catastrophe. Demand to visit the Soviet-era site including the abandoned city of Pripyat has surged, with Chornobyl-Tour expecting 150,000 bookings this season, double last year’s number. The Ukrainian government struggled for years to maintain awareness of the 1986 disaster, which rendered parts of the countryside uninhabitable for 24,000 years. \--With assistance from Kathleen Hunter and Tim Ross.To contact the author of this story: Rosalind Mathieson in London at rmathieson3@bloomberg.netTo contact the editor responsible for this story: Karl Maier at kmaier2@bloomberg.net, Anthony HalpinFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.