The border between Egypt and Gaza has become a major point of contention in the negotiations over a cease-fire to end the war in Gaza — not just between Israel and Hamas, but also between Israel and Egypt.

Israel’s prime minister, Benjamin Netanyahu, says the country must occupy the border area to prevent Hamas from smuggling weapons into the Gaza Strip from Egypt’s Sinai Peninsula. He has cast control of the Philadelphi Corridor, as the border zone is known, as a matter of existential importance for Israel, though some Israeli politicians believe he is using the issue to avoid reaching a deal for a cease-fire and the release of hostages.

Egypt argues that it has already cracked down on smuggling there — because doing so serves its own security interests, not just Israel’s — by building barriers, destroying tunnels and patrolling the area. For Cairo, accepting Israeli troops on the border would threaten its own national security and draw criticism from the Egyptian public, analysts say.

The increasingly bitter dispute has destabilized the once strong security partnership between Egypt and Israel, whose landmark 1979 peace treaty has been a linchpin of Middle East geopolitics for decades.

Here’s a look at the issue.

What has Hamas been able to smuggle through the border?

Exactly how much Hamas has been able to smuggle into Gaza via the Gaza-Egypt border — above ground or through tunnels — is unknown.