As Israel’s army prepared to launch its ground assault on Gaza City, and days after Israel tried to assassinate Hamas leaders in Qatar, Secretary of State Marco Rubio’s visit to Israel this week was inevitably dominated by discussions of the war. The Doha strikes likely ended any near-term prospects for a cease-fire and dimmed hopes of freeing Israel’s remaining hostages. The new military operation in Gaza, now underway, will prolong the suffering of its roughly 2 million residents.

While it deservedly gets most of the attention, Gaza is far from the only looming crisis on Israel’s borders. The past several weeks have also seen an acceleration of Israeli plans to take over — if not formally annex — the West Bank, a development that would almost certainly lead to more violence and further turn Israel into a pariah state in the eyes of most of the world.

For the last two years, extreme-right nationalists in the current Israeli government — who have long dreamed of extending Jewish control to both Gaza and the West Bank — are taking advantage of the war in Gaza, their political stranglehold over Mr. Netanyahu, Palestinian leadership disarray and what amounts to a green light from the Trump administration to implement that dream. Without international action to stop it, it could soon become reality, and a nightmare for Israelis and Palestinians alike.

Israel’s creeping takeover of the West Bank has, of course, been decades in the making. The population of Israeli settlers there and in East Jerusalem has grown to about 740,000 today from around 10,000 in the early 1970s. But the expansion of settlements and illegal outposts is accelerating, with more than a hundred new developments established over the past year alone.

On Aug. 20, Israeli defense ministry planning authorities in the West Bank approved a large settlement bloc called E1. The plan, often called the “doomsday” settlement by proponents of a two-state solution, would make it nearly impossible to create a contiguous Palestinian state, by physically separating the Palestinian-populated cities of East Jerusalem, Ramallah and Bethlehem.

In announcing the plans to move forward with E1, Finance Minister Bezalel Smotrich said the quiet part out loud, stating the settlement “buries the idea of a Palestinian state.” That notion was echoed last week by Mr. Netanyahu, who, while signing an agreement to press ahead with E1, said: “We are going to fulfill our promise that there will be no Palestinian state. This place belongs to us.” At a news conference in Jerusalem on Sept. 3, Mr. Smotrich presented a plan to formally annex roughly 82 percent of the West Bank, which would isolate Palestinians into small enclaves while Israel unilaterally took formal ownership of the rest. Mr. Netanyahu has not endorsed the plan, nor does it have a majority of public support. But the prime minister has backed at least partial annexation in the past and more recently hinted that European plans to recognize a Palestinian state could prompt Israel to respond with its own “unilateral actions,” which might include annexation.