Since the Six-Day War of 1967 against four Arab armies, Israel’s doctrine of defensible borders has evolved. Driven by the vision and influence of former Foreign Minister Yigal Allon, Israel’s defensible borders doctrine addressed its pre-war vulnerabilities to the East and its narrow coastal plain to the West, along the Mediterranean Sea. Israel’s lightning victory in the Six-Day War resulted in both topographical advantage and strategic depth opposite Jordan to the East and Syria to the North, through the newly conquered Golan Heights. This newfound strategic advantage would protect Israel’s main transportation arteries and its large coastal cities, from Ashdod in the South to Haifa in the North, where roughly 70% of Israel’s population lives and about 80% of its industry is located.
Over the course of the last half-century, and particularly since Hamas’s October 7, 2023, invasion, massacre, and abduction of hundreds of innocent civilians, Israel’s security concept has undergone a fundamental shift. The horrors that Israel experienced on that fateful day were part of a larger Iranian regime strategy that sought to dissect the country in half, by the Iranian proxy Hamas in the South and by its Hizbullah proxy in the North. The lessons of October 7 underscored the essential importance of protecting all of Israel’s borders by demilitarizing the territory beyond the border, creating broad buffer zones, enabling Israel’s control, monitoring mechanisms, with strategic depth and maneuverability. This reflects the importance of expanding the defensible borders doctrine to effectively defend Israel from the East, the South, and the North.
In the South, establishing a buffer zone and demilitarized belt inside the Gaza Strip under Israeli control, including along the border between Gaza and Egypt, is essential to establish minimal strategic depth to prevent a repetition of Hamas’s October 7 invasion. Before the attack, the lack of strategic depth between Israel’s Gaza-envelope communities and the Gaza Strip rendered them virtually defenseless against a mass terror assault. Moreover, the porousness of the Gaza-Egyptian border, where tons of weapons, ammunition, and contraband were smuggled to Hamas, reflects similar strategic and existential vulnerabilities.
In the North, Israel has faced ongoing threats of Hizbullah terrorist infiltration through the Lebanon-Israel border, where the group has burrowed tunnels. On the Syrian-Israeli border, the collapse of Syria’s Assad regime and the ascendance of competing jihadi groups pose an additional threat to Israel. Radical Islamist militias have threatened to invade Israel and Israeli military positions near the Golan Heights. These threats require Israel to establish buffer and demilitarized zones of approximately 15–20 kilometers beyond the border with Syria. IDF presence on the Syrian side of the Golan Heights, including Mount Hermon towards Damascus, has created that buffer zone.
In Lebanon, too, Israel has established a buffer and demilitarized zone of a few kilometers. These areas must extend at least to the Litani River and, in certain places, beyond it to prevent hostile direct fire at Israeli communities and the threat of invasion. Israel learned painful lessons from its unilateral withdrawal in 2000, given the fragility of the country’s truncated borders. Israel will always need to defend itself from ongoing threats from jihadi groups, whether Iran-backed Shiite Hizbullah or radical Sunni terrorists. Buffer zones will anchor, stabilize, and secure the fledgling anti-Hizbullah government, bolstering their efforts in demanding that Hizbullah and other terrorist actors disarm. Demilitarization and buffer zones provide a security advantage to Israel and other regional ethnic minorities, such as the Druze and Kurds in Syria.
Opposite Egypt, Israel should seek a full demilitarization of the Sinai approaches to Gaza, as set in the 1979 Israel-Egypt Peace Treaty’s military annex.
From an international perspective, defensible borders for Israel also constitute a vital condition for the U.S. administration’s “America First” policy in the Middle East. Safeguarding these borders is a shared interest for Israel and the United States, which seeks to ensure regional stability, enabling economic prosperity in cooperation with leading states such as Saudi Arabia.
Additionally, defensible borders in Judea and Samaria, particularly securing and holding the Jordan Rift Valley and the Judea-Samaria hill ridge, constitute unconditional security requirements for any prospective Palestinian entity there.
For any possible IDF redeployment to new security lines, Israel requires the reliable verification and well-monitored disarmament and the dismantlement of Hizbullah and other Islamist terrorist groups in Lebanon and Syria, and of Hamas in Gaza. These unconditional security prerequisites would run in parallel with new border security arrangements in cooperation with neighboring state military forces that could ultimately replace Israeli security presence. Particularly after the atrocities of October 7, establishing Israel’s defensible borders in the South, North, and East constitutes an existential security requirement and a critical cornerstone of a stabilized and prosperous Middle East region.
