Two grave developments endangered the fragile Egyptian-mediated cease-fire reached on May 30 between Hamas and Israel following last week’s intense flare-up of hostilities. The first was the renewal of Palestinian protests along Gaza’s border fence with Israel on June 1 and the subsequent killing of volunteer paramedic Razan Najjar by Israeli soldiers the next day. In the second incident, several mortar shells were fired from Gaza toward Israeli border communities, probably by what Israel dubs “renegade” Palestinian factions that do not accept Hamas control. The shelling may have been retaliation for the killing of Najjar, whose funeral drew tens of thousands of mourners, a turnout only seen in the past for Hamas leaders killed by Israel.

Every such incident is a reminder that even if neither side wants to engage in a broad military clash, as long as Gaza is so unstable, there is no guarantee that understandings reached between the sides will hold.

The next event that will test the cease-fire is a June 5 protest against Israel’s victory over Arab armies in the 1967 war and its occupation of Gaza. Hamas had recently marked several key dates for mass demonstrations by the fence. The June 5 “Naksa Day" (Arabic for “setback”) is shaping up as another challenge to the Israel-Hamas understandings reached last week and to soldiers of the Israel Defense Forces (IDF) tasked with preventing Palestinian protesters from breaching the border fence.

In addition to military preparations for the demonstration out of concern that it could deteriorate into the extensive violence that resulted in the deaths of over 100 Palestinians and wounding and maiming of thousands in clashes last month, Israel is also taking diplomatic steps to prevent events from spiraling out of control. Israel conveyed a message to Hamas indicating that June 5 would determine the prospects of easing the Gaza siege and reaching a long-term truce. This is the first time since it imposed its siege on Gaza following the Hamas takeover of the Strip in 2007 that Israel has openly discussed an arrangement with Hamas.