The oddly cordial relationship between Barack Obama and Donald Trump took a wholly predictable turn Wednesday, when the president-elect lashed out at the president on Twitter, apparently in response to the outgoing administration’s move not to veto a United Nations resolution demanding that Israel “immediately and completely cease all settlement activities in the occupied Palestinian territory” and declaring the establishment of such settlements illegal.

“Doing my best to disregard the many inflammatory President O statements and roadblocks,” Trump seethed. “Thought it was going to be a smooth transition—NOT!” The Republican followed up with a pair of tweets appearing to clarify that his outburst stemmed from Obama’s decision to allow the U.N. resolution to proceed—a maneuver at odds with Trump’s more hawkish position.

The incoming president has repeatedly signaled that he will fully align himself with the right-wing Likud government of Benjamin Netanyahu, who responded to Trump Wednesday by thanking him for his “clear-cut support” and tagging two of his adult children, Ivanka and Donald Jr. (Trump’s pick to serve as U.S. ambassador to Israel, David Friedman, has compared Jewish opponents of Israeli settlements to Nazi collaborators.)

The clash over Israel is only the latest in a series of flash points between the president and president-elect, who held an outwardly conciliatory meeting shortly after the election, and who have reportedly continued to speak over the phone. The relationship became shakier as Obama grew bolder in his denunciations of Vladimir Putin, following reports from both the F.B.I. and the C.I.A. that Russia engaged in a protracted cyber campaign to help elect Trump and undermine his opponent. Trump has cast doubt on claims that he was aided by Russian meddling in the election, and has lashed out on Twitter at critics who point out he lost the popular vote by nearly 3 million votes.

Shortly after his online outburst, a Gallup poll named President Obama the most admired man in America, while Trump came in a distant second. Hillary Clinton was named the country’s most admired woman for the 15th year in a row.

Naturally, Trump’s latest tantrum comes just days after his communications team assured reporters that the relationship between the two men couldn’t be better. “From the current president on down to his senior staff, [the] current White House has been unbelievably gracious with their time, advice, and opinions to the president-elect and to his senior staff, so far, [with] making this transition as smooth as possible,” incoming White House press secretary Sean Spicer said last week.