As the first phase of the cease-fire between Israel and Hamas winds down this weekend, the future of the truce remains murky. What happens in a key strip of land along the border between Egypt and Gaza in the coming week could provide an indication of how things will move forward.

Israel is supposed to begin withdrawing troops on Sunday from the border area, known as the Philadelphi Corridor, and leave it completely by the following weekend. Benjamin Netanyahu, the Israeli prime minister, has long said that Israeli control there is a core security national interest, injecting uncertainty over this step.

Here’s what to look for in the coming days.

What is the Philadelphi Corridor?

An eight-mile strip of land that divides Gaza from Egypt, the Philadelphi Corridor emerged as a major sticking point in cease-fire talks between Israel and Hamas. The border, which divides the city of Rafah, was set up under the Egypt-Israel peace treaty of 1979.

After Hamas seized full control of Gaza in 2007, its fighters and officials oversaw the enclave’s border with Egypt and the Rafah crossing, the only exit from Gaza to the outside world not directly overseen by Israel.

Israeli officials have argued that Hamas smuggled in arms and materiel for its fighters from across the Egyptian border. In September, Mr. Netanyahu called the Philadelphi Corridor “Hamas’s oxygen valve.”