The countries announced in 2017 that they would withdraw from the UN Educational, Science and Cultural Organization, accusing it of bias against Israel. That went into effect at the stroke of midnight.
That was a bit of an eyebrow raise, but here is what UNESCO actually did, to cause the US and Israel to walk away from it:
THE HORROR! UNESCO actually identified one site as Palestinian World Heritage site only!!!! That means (panic attack/trembling in Tel Aviv) there must have been a Palestine around here somewhere! But we say Palestine never existed, does not exist, AND WILL NOT EXIST, NO MATTER HOW MUCH THE UN RECOGNISES THEM!
Unfortunately, this is most likely going to serve to marginalize the US and Israel even further from the realm of international cooperation more than leadership of both countries can possibly know.