President Donald Trump should not meet Vladimir Putin until the Russian president also agrees to a joint meeting with Ukrainian President Volodymyr Zelensky.

Unfortunately, while White House officials first suggested that Trump would hold to that principle, Trump later said he was open to meeting Putin without Zelensky. It is concerning that this about-face followed Putin’s statement that any meeting with Zelensky required “certain conditions” that were still “a long way from” being created.