The mood in Jerusalem was festive. Jared Kushner and Ivanka Trump were in town to attend the new US Embassy opening, alongside Israeli Prime Minister Benjamin Netanyahu and US Treasury Secretary Steve Mnuchin. President Donald Trump gave a televised speech from Washington, insisting that America’s “greatest hope” for Israel is “for peace.”

Just 60 miles away, in the starkest contrast imaginable, Israeli soldiers were firing on Palestinian protesters at the Gaza border to protest the embassy move, demonstrations that were part of a protest wave ongoing since March. Most of the protesters were unarmed, though some threw rocks and Molotov cocktails; the Israeli military reported at least one attempt to detonate a bomb at the border during a demonstration.

Before and during the embassy opening ceremony, 40,000 Palestinians marched toward a border fence defended by Israeli soldiers. The Israelis responded with live ammunition, killing more than 50 Palestinians and injuring another 2,400 (per the Gaza Health Ministry). No Israeli soldiers were killed or wounded.

The contrast between these two events is profoundly jarring. While American and Israeli luminaries attended a high-level diplomatic event, in which Israel’s prime minister declared that “this is a great day,” people were literally dying just dozens of miles away. AFP journalist Patrick Galey has, on his Twitter feed, been juxtaposing two photos taken around the same time: one from the embassy opening, the other from the Gaza protests. The contrast lays bare both the harsh reality of what’s happening and the utter irresponsibility of Trump’s decision to move the embassy in the first place:

This violence was eminently predictable. Though Israel’s government is based in Jerusalem, and Congress had passed a law in 1995 requiring the US to move its embassy from Tel Aviv to the holy city, US presidents had repeatedly issued a waiver blocking the move from taking place. The logic was very clear: Jerusalem is one of the major flashpoints in the Israeli-Palestinian conflict, with both Israelis and Palestinians claiming the city as rightfully theirs.

Moving the US Embassy would be a sign that the United States was recognizing the city as Israeli without also recognizing the Palestinian claims to it, a move that would anger Palestinians and jeopardize America’s broker status in peace talks. Experts on the conflict warned that moving the embassy would be like lighting the fuse on a powder keg; the Israeli-Palestinian situation is perpetually on the brink of violence, and doing something like this risked kicking off another round of conflict.

Trump ignored this advice, officially announcing the plan to move the embassy in December. Initially, the response to the announcement from Palestinians and the broader Arab world was relatively muted, suggesting that fears of renewed conflict may have been overblown. But today’s events — the deadliest day in the Israeli-Palestinian conflict since the 2014 Gaza war — proves that they weren’t entirely off base.

Trump didn’t create a tense situation on the Gaza border; there had been months of conflict between Israeli forces and Palestinian protesters, stoked by Hamas (the radical Islamist group that controls Gaza). But doing something so obviously inflammatory, with little obvious strategic upside to the United States, was irresponsible and dangerous. The question now is whether today’s carnage will be the exception — or whether we’re seeing the start of a new round of violence that could easily spin out of control.

To learn more about the situation in Gaza, listen to the May 15 episode of Today Explained.