A report last week in Ma’ariv that fundamental disagreement between Palestinian and Israeli negotiators over the future of the Jordan Valley may soon collapse peace talks comes as no surprise to Middle East observers. Palestinian rejection of Israel’s security requirement of an IDF presence along the Jordan River is not new.The Palestinian leadership rejected former prime minister Ehud Barak’s compromise offer at Camp David in 2000 to place Israeli security forces in the Jordan Valley on the soil of a prospective demilitarized Palestinian state. Prime Minister Binyamin Netanyahu’s current defense claims and Barak’s previous security demands in the Jordan Valley can be considered minimal compared to former prime minister Yitzchak Rabin’s insistence on Israeli sovereignty in the Jordan Valley in order to defend Israel’s main airport and coastal cities.Rabin declared to the Knesset plenum in October 1995, as it endorsed the Oslo II interim accords, that “the security border for defending the State of Israel will be in the Jordan Valley, in the widest sense of that concept.”Historical context is important. Since 1967 Israeli governments have been guided by the security doctrine of “defensible borders,” that depends on the Jordan Valley and the rising 900-meter Judea- Samaria hill ridge as Israel’s front line of defense against conventional assaults and terror attacks from the east.In the wake of the Islamist ascendancy in the region over the past few years, the movement of radical Islamic operatives and weaponry across the Middle East and especially in and out of countries near Israel such as Syria, Lebanon, Iraq and Egyptian Sinai, as well as Hamas-controlled Gaza, the defensible borders thesis has been vindicated.Israel’s Jordanian neighbor has understood the importance of the Jordan Valley as its western front line of defense. The Hashemite Kingdom relies on Israel as its one neighbor that has maintained ironclad security along its 335-kilometer shared border and prevented terror groups and weaponry from reaching radical Islamic groups in PA-controlled areas of Jordan’s former West Bank that could be used against Jordan and Israel.Jordan has also aggressively defended its border with Israel and has prevented numerous attempts by terrorists to infiltrate the Jewish state. Jordan’s security sense has been heightened in view of Syrian regime threats to attack it due to Jordan’s support of some of the Syrian opposition. Jordan’s collective memory is seared by al-Qaida’s 2005 terror assaults against major Jordanian hotels and government buildings in Amman that killed 60 people and wounded hundreds.Jordan’s sensitivity to constant threats of destabilization has placed it in a delicate position regarding a prospective Palestinian state on its border.King Abdullah II has publicly supported the establishment of a Palestinian sovereign state in the West Bank. However, the king and his security echelons are mindful of the Palestinians’ “checkered” security record, and have reason to be concerned.Clearly, Jordan seeks to avoid a repetition in their own backyard of the massive increase in Hamasand al-Qaida-associated terror activity in Egyptian Sinai and against Israel following Israel’s 2005 unilateral disengagement from the Gaza Strip.ISRAEL’S WITHDRAWAL of its security presence in the Philadelphi Corridor that lies in between the Gaza Strip and Egyptian Sinai resulted in a vast, Hamas-engineered terror tunnel network that resulted in the smuggling of major weapons arsenals into the Strip.Jordan is likely aware that rocket fire against Israel increased by 500 percent between Israel’s withdrawal in 2005 and 2006 while Hamas and other jihadi groups fired upgraded medium-range rockets, hitting Jerusalem’s environs, not too far from Jordan’s border with Israel.Both the king and his closest advisers are also keenly aware that in the event of an Israeli withdrawal, the Jordan Valley could easily be transformed into the “Philadelphi Corridor” of the West Bank.With the West Bank under prospective Palestinian control, jihadi groups from Iraq and Syria would be attracted to cross into Jordan and then to Palestinian territory. A common Palestinian-Jordanian border would also likely increase Palestinian irredentism towards the East Bank, which has been a major Jordanian concern since “Black September” in 1970, when Syrian-backed Palestinian insurgents threatened the Hashemite Kingdom.Jordanian security concerns may help explain why various senior Jordanian officials have told their Israeli counterparts regularly over the past decade that if a Palestinian state is established, it must be demilitarized, and the Palestinian leadership must agree that the Israeli and Jordanian security forces will be the only two armies between the Jordan River and the Mediterranean Sea.The writer is a foreign policy fellow of the Jerusalem Center for Public Affairs, and an adjunct fellow of the Washington, DC-based Hudson Institute. He served as the secretary-general of the World Jewish Congress from 2011 to 2013.