Prime Minister Shinzo Abe is nothing if not an optimist. He had hoped that last week's Osaka Group of 20 leaders summit would tackle difficult global problems and reinvigorate multilateral diplomacy in the process. It was going to be a tough sell: There are yawning differences in views among G20 members and recent events have magnified those divisions. Ultimately, Abe's efforts were undone by an unsolvable dilemma: producing a consensus meant leaching the final declaration of any substance.

While the G20 process is a long and plodding series of conferences that culminates in the leaders' meeting, the days before the Osaka sit-down and the meeting itself were laden with drama. There was the much-anticipated dinner between U.S. President Donald Trump and Chinese President Xi Jinping, at which they would hopefully resolve their trade war. There was a meeting between Trump and Russian President Vladimir Putin, in which the U.S. president made light of the charges of Russian interference in U.S. elections. British Prime Minister Theresa May had a frosty encounter with Putin, during which he dismissed the murder of a former Russian spy on British soil as "not worth serious interstate relations." Putin's remarks about "the end of liberalism" in an interview before the meeting also prompted tough-minded rejoinders from participants.

Saudi Arabian Crown Prince Mohammad Bin Salman was present and center stage, seeming absolved of any involvement in last year's brutal murder of journalist Jamal Khashoggi. Then there were Trump's comments that Japan was freeloading on the Japan-U.S. security alliance and his casual invitation to North Korean leader Kim Jong Un to join him for a handshake at the Demilitarized Zone during his Sunday visit.