On Monday the Security Council endorsed President Trump’s 20-point peace plan for Gaza, ratifying for the first time the requirements that Hamas disarm and Gaza be demilitarized.

The Security Council’s backing offered a scaffolding of international legitimacy that will be needed to persuade countries to help see the plans through.

The fraught path ahead was made clear even before the delegates took to their desks, with Israeli Prime Minister Benjamin Netanyahu — under pressure from his far-right coalition partners — denouncing ...