Defensible Borders for Israel: Questions and Answers

The doctrine dates to the aftermath of the 1967 Six-Day War and is associated first with former Foreign Minister Yigal Allon, who addressed Israel's pre-war vulnerability in the east and along its narrow coastal plain. It was carried forward by Prime Minister Yitzhak Rabin and anchored in Resolution 242 and the Bush letter of 2004.

Dr. Dan Diker traces the line from Allon's post-1967 planning through Rabin's last Knesset address of October 5, 1995, delivered when he presented the Oslo II Interim Agreement for ratification. Rabin stated that the security border of Israel would be located in the Jordan Valley, in the broadest meaning of that term, and that Israel's permanent borders would lie beyond the pre-1967 lines. His formulation carries weight because it came from the prime minister who signed the Oslo Accords, one month before his assassination.

The Jerusalem Center's Defensible Borders program itself dates to 2004, beginning with a joint conference with the Knesset Foreign Affairs and Defense Committee and continuing through two decades of published studies. Before 1967, Israel's waist measured roughly nine miles between the Mediterranean and the 1949 armistice line.

There is no single, uniform width. The necessary distance varies with the threat, the terrain, weapons range, the proximity of communities, and the ability to monitor demilitarization. JCFA analyses discuss three kilometers or more in Gaza, southern Lebanon up to the Litani, and a 15–20 kilometer demilitarized zone in southern Syria.

Brig.-Gen. (res.) Yossi Kuperwasser argues that Gaza's zone should be wide enough to expose and intercept infiltrators before they reach Israeli communities. Dr. Dan Diker notes that the IDF established zones extending up to three kilometers along the Gaza perimeter and a 15–20 kilometer demilitarized area in southern Syria, while emphasizing that topography and operational requirements — not an arbitrary number — determine effective defensive depth. For Lebanon, Oded Ailam proposes a 10–15 kilometer demilitarized area, extending farther where strategically important terrain requires it.

These are strategic assessments and proposals, not established international boundaries.

Following October 7, the IDF established buffer zones extending up to three kilometers along the Gaza perimeter, and JCFA and JISS research sets the requirement at three kilometers or more. Their purpose is to prevent a repeat ground invasion and to enforce the demilitarization that the 2005 disengagement failed to secure.

Kuperwasser's Gaza analysis argues that Israel's prewar security concept failed because it underestimated Hamas, permitted its military build-up, and left Israeli communities without adequate defensive depth. He proposes a demilitarized buffer alongside continuous readiness and operational freedom — while expressly opposing the re-establishment of Israeli civilian settlements in Gaza under present conditions.

The 2005 precedent is central to the argument. After the unilateral withdrawal that removed some 9,000 Israelis, Hamas accumulated an arsenal exceeding 30,000 rockets, mortars, and drones, built an underground network of some 500 kilometers, and trained forces capable of complex combined-arms operations.

The Jordan Valley is conceived as Israel's eastern security barrier. Its width, its steep eastern approaches, and its control of the routes from Jordan toward Israel's population centers are intended to prevent weapons smuggling, hostile-force deployment, and a rapid attack from the east.

Dr. Dan Diker traces this position to Prime Minister Yitzhak Rabin's statement of October 5, 1995, that Israel's security border should remain in the Jordan Valley in the broadest meaning of that term. The doctrine pairs the valley with the Judea and Samaria mountain ridge roughly 3,200 feet above it — the high ground that commands Israel's coastal plain, its main airport, and the majority of its population.

Amb. Dore Gold argued that international forces could supplement, but should not replace, Israel's ability to defend this corridor. The valley's final political status remains one of the central disputes in any Israeli–Palestinian settlement.

Terrain determines what forces can see, defend, and reach. High ground provides observation and early warning; valleys and narrow corridors channel movement; insufficient depth can place civilian communities within minutes of an infiltration force. Surveillance technology helps, but it can be disabled, deceived, or overwhelmed — as it was on October 7.

Maj.-Gen. (res.) Yaakov Amidror, a former Israeli national security advisor, explains that a border lying beneath hostile commanding terrain is inherently more difficult to defend. Dr. Dan Diker consequently argues that buffer-zone dimensions must reflect ridgelines, approach routes, population centers, and warning time rather than a uniform number of kilometers.

In JCFA's analysis, the 2005 disengagement is the doctrine's central negative precedent: a complete territorial withdrawal, unaccompanied by verified demilitarization, that was followed by the largest military build-up ever assembled by a non-state actor on Israel's borders.

Dr. Dan Diker documents the sequence: a unilateral withdrawal that removed some 9,000 Israelis from their homes, followed by a Hamas arsenal exceeding 30,000 rockets, mortars, and drones, an underground tunnel network of some 500 kilometers, and forces trained for complex combined-arms operations.

The conclusion drawn is not that withdrawal is impossible but that it must be sequenced. Demilitarization must be absolute, verified, and enforced before a security presence is reduced — not promised in exchange for it. The Israeli public has reached a similar assessment: 56 percent now describe the 2005 disengagement as a strategic mistake.

A security zone is a military space established to separate hostile forces, provide warning time, or enforce demilitarization. A settlement is a permanent civilian community. The presence of soldiers, observation posts, and defensive infrastructure does not by itself create a civilian settlement or constitute a sovereignty claim.

The distinction is reflected in Kuperwasser's Gaza analysis: he advocates a demilitarized buffer and continuing military readiness while expressly opposing the re-establishment of Israeli civilian settlements in Gaza under present conditions. A zone's duration and conduct may still raise serious legal questions, but military control and civilian settlement are factually and legally different policies.

According to JCFA's legal analysis, yes — but not as an unlimited or automatic right. International law permits security and demilitarization zones when they are established by agreement, authorized through international arrangements, or maintained as a necessary and proportionate response to a continuing armed threat.

Amb. Alan Baker, former Legal Adviser and Deputy Director-General of Israel's Ministry of Foreign Affairs, points to precedents including the Egyptian–Israeli arrangements in Sinai, the 1974 Israel–Syria disengagement agreement, and the UN-supervised arrangements in southern Lebanon. He argues that Israel may insist on monitored security zones while a real and immediate danger continues to emanate from neighboring territory — particularly where previous international mechanisms failed to prevent hostile forces from returning.

The legal argument is conditional. A zone must serve a genuine security purpose, remain connected to the continuing threat, and comply with the rules governing military necessity, proportionality, civilian protection, and occupation where applicable. Its legality is disputed internationally when maintained unilaterally inside another state's territory, and it cannot lawfully become a pretext for permanent territorial acquisition.

Resolution 242 called for withdrawal of Israeli armed forces from territories occupied in the 1967 conflict, alongside the termination of belligerency and the establishment of secure and recognized boundaries. It did not expressly require withdrawal from all territories or a return to the prewar lines.

JCFA's analysis of Resolution 242 argues that the omission of the definite article before territories in the original English text was deliberate and left the final boundaries to negotiation. Other interpretations dispute how much legal significance that omission carries, but the resolution plainly linked withdrawal to a negotiated settlement rather than prescribing a specific border. The full text is available from the UN Digital Library.

Resolution 242 also contemplated measures including the establishment of demilitarized zones, which is why JCFA's legal argument treats demilitarization as internal to the resolution rather than as a departure from it.

In his letter to Prime Minister Ariel Sharon, President George W. Bush reiterated the United States' commitment to Israel's security, including secure and defensible borders. The letter is the clearest American endorsement of the principle that a final border need not replicate the 1967 lines.

The letter and the accompanying White House press availability of April 14, 2004 are held in the George W. Bush presidential archives; the text is also reproduced by the United Nations. It is cited throughout JCFA's research as the diplomatic anchor of the doctrine, alongside Resolution 242 and Rabin's 1995 Knesset address.

It is an expression of policy by one administration rather than a binding instrument, and successive administrations have restated American commitments in their own terms.

It may be. Under Article 42 of the Hague Regulations, occupation turns on whether foreign forces exercise effective authority over territory — not on whether they describe their presence as temporary, defensive, or a security zone. A prolonged Israeli presence exercising effective control inside Lebanon or Syria could therefore qualify as occupation, triggering the applicable duties of occupation law.

Amb. Alan Baker's argument is that an ongoing threat may justify maintaining and supervising a defensive zone. That possible self-defense justification does not automatically eliminate obligations under occupation law, authorize annexation, or permit indefinite control once military necessity has ended. The text of Article 42 of the 1907 Hague Regulations is published by the International Committee of the Red Cross.

JCFA experts argue that they could — if they demonstrated the ability and willingness to disarm Hizbullah and prevent its return. The record under Resolution 1701 left Israel skeptical.

Amb. Dore Gold documented how Hizbullah rebuilt military infrastructure south of the Litani despite the presence of UNIFIL and the Lebanese Armed Forces. The UN Secretary-General's own reports on the implementation of Resolution 1701 catalogue restrictions on UNIFIL's freedom of access and movement and the state of the arms embargo across successive reporting periods.

Oded Ailam therefore proposes a stronger U.S.-led multinational force working with the Lebanese army, accompanied initially by Israeli monitoring and freedom of action. In this framework an effective alternative could eventually replace Israel's direct presence; promises or lightly enforced mandates could not. In the June 2026 survey conducted for JCFA, 65 percent of Israelis said they do not trust international forces to replace the IDF along Israel's borders.

A nationwide survey conducted for JCFA by Lazar Research under Dr. Menachem Lazar, published June 22, 2026, with a representative sample of 503 Jewish and Arab Israeli adults, found broad majorities supporting security zones on every front and deep skepticism toward international guarantees.

The survey found that 73 percent support maintaining an IDF presence and security zone in southern Lebanon up to the Litani, against 14 percent opposed; 64 percent support a permanent military buffer zone in Gaza, with a further 11 percent favoring a temporary arrangement; 60 percent support maintaining Israel's presence in areas secured in Syria after the fall of the Assad regime; and 57 percent regard a permanent presence in the Jordan Valley as a non-negotiable security need, against 11 percent who would relinquish it.

On alternatives and precedent: 65 percent do not trust international forces to replace the IDF; 61 percent oppose an agreement requiring full withdrawal from Judea and Samaria without Israeli-controlled buffer zones or security mechanisms, against 27 percent in favor; 48 percent now regard the Oslo Accords as a strategic mistake, and 56 percent say the same of the 2005 Gaza disengagement.

The central requirement is a reliable security mechanism capable of replacing Israeli forces: verified disarmament or removal of hostile forces, prevention of weapons smuggling and military reconstruction, deployment of capable state forces, effective monitoring, and rapid response to violations.

Amb. Alan Baker ties the justification for Israeli supervision to the persistence of a real and immediate danger. Oded Ailam proposes gradually reducing Israeli freedom of action as the Lebanese army and a credible multinational force demonstrate that they can enforce demilitarization. Dr. Dan Diker frames any IDF redeployment to new security lines as conditional on reliable verification and the monitored dismantlement of Hizbullah in Lebanon and Syria and of Hamas in Gaza.

The exit test is therefore measurable security performance — not an arbitrary date, and not an indefinite presence.