By the end of this year, Israel is expected to become the second country after the United States to declare Initial Operational Capability for its F-35s. Already, Tel Aviv has taken possession of five of the multirole fighters, and following an agreement late last month to buy an additional seventeen planes, will ultimately purchase fifty planes. All fifty F-35s are scheduled to be delivered by the end of 2024.

Israeli officials typically describe the F-35s purpose as ensuring the country’s continued air superiority in the region. In particular, they focus on how the plane’s stealth capabilities will allow them to evade Iran’s increasingly capable, Russian-built air defense systems. One mission that is not being discussed is that Israel will likely use its F-35s as a nuclear delivery system.

Although the government refuses to officially acknowledge it, Israel is known to have a nuclear arsenal with as many as 100 warheads. The Jewish State is also believed to possess a nuclear triad, consisting of ground-based Jericho missiles, Dolphin-class submarines equipped with sea-launched cruise missiles and some combination of nuclear-capable aircraft.

It’s likely that the F-35 will be the newest addition to the air leg of Israel’s triad. This technically should cause some diplomatic problems with the United States. Previously, in order to purchase the A-4 Skyhawk and F-4 Phantoms from the United States in the 1960s, Israel agreed not to use U.S.-supplied aircraft as nuclear delivery systems. Before acquiring the F-4 Phantoms, for instance, the United States requested and received assurances that Israel would not “use any aircraft supplied by the United States as a nuclear weapons carrier.”

At the same time, Israel also assured the United States that it would not “introduce” nuclear weapons in the Middle East, which Israel interpreted to mean it could build a nuclear arsenal as long as it didn’t publicly acknowledge its existence. It’s possible Israel attaches a similarly tortured interpretation to its pledge not to use U.S. aircraft as nuclear weapon carriers. As Hans M. Kristensen and Robert S. Norris have pondered, “What do ‘use’ and ‘carrier’ mean? Do they refer to equipping an aircraft with the capability to deliver nuclear weapons or do they refer to the act of employment itself?” Kristensen and Norris also point out that “it is not known if Israel made similar pledges when it acquired F-15 and F-16 aircraft in the 1980s and 1990s.” Regardless of what pledges were or were not made, Kristensen and Norris judge that some of Israel’s F-15s and F-16s are nuclear capable.

If true, it would only make sense that Israel’s F-35s would be a nuclear-capable aircraft, as Tel Aviv’s Joint Strike Fighters are supposed to replace its current fleet of F-16s. Furthermore, the Israeli F35s will be based on the F-35A variant of the Joint Strike Fighters. This is significant because the United States and some of its allies are planning to equip part of their F-35A fleet with America's B61-12 nuclear gravity bomb.

Of course, Israel doesn’t have access to the B61-12 bomb, and some have doubted Israel’s ability to refit the planes in order to carry its indigenous nuclear warheads. “Changing the internal wiring and engineering of the plane to accommodate a different warhead could be done, but not without significant challenges,” one analyst told War is Boring in 2014. “Especially for a plane that’s had the extensive engineering challenges that have been the hallmark of the F-35 program.”

Similar arguments were made in the past, only to turn out to be wrong. This time is unlikely to be any different. When the United States was considering selling Pakistan F-16s in the 1980s, many argued that Islamabad lacked the technical sophistication to turn these into nuclear-capable aircraft. That turned out to be false. Furthermore, as noted above, there is good reason to believe that Israel has already retooled U.S. planes like the F-16 to carry nuclear weapons. Although the F-35 is more technically challenging, there is little reason to think Israel’s advanced defense industry cannot overcome these obstacles.

One way that the United States could try to prevent Israel from transforming the F-35 into a nuclear delivery system is by prohibiting Tel Aviv from making any changes to the plane. This is actually the policy the United States has adopted toward allies that have purchased the F-35s. As Wired has reported: “The [F-35] stealth fighter jet, which Lockheed Martin is selling to US allies, comes with caveats that expressly prohibit unauthorized tinkering and a requirement that only US-run facilities service the plane. These rules, designed to protect deeply intertwined systems and maintain the security of sensitive technology, are non-negotiable.”

The only exception to this rule is Israel. While every other F-35 operator will be prohibited from making any changes without America’s permission, Israel will be allowed to install its own custom software and weapon systems, as well as do its own maintenance. The head of Israel’s main air force testing center has said: “All our platforms have been upgraded to enable stretching the flight envelope while using the unique weapon systems made by Israeli industry.” Since Israel already intends to refit its F-35s to carry Israeli-specific weapons, its defense industry can surely equip some to carry indigenous nuclear gravity bombs. Moreover, the stand-off missiles Israel is putting on its F-35s can carry a heavy enough payload to support a nuclear warhead.

Thus, there is no reason to think that Israel doesn’t have the technical capability to make its new F-35s nuclear capable. And, even those who doubt that Israel can refit its F-35s to carry nuclear bombs don’t dispute that Israel would want this capability. As one analyst put: “If Israeli F-35s can carry nukes, or if the ever-inventive Israeli defense industry can modify them to do so, then Israel could possess an atomic strike plane able to penetrate Iranian air defenses in the event of full-scale war.”

Zachary Keck (@ZacharyKeck) is the Wohlstetter Public Affairs Fellow at the Nonproliferation Policy Education Center.

Image: Flickr / Times Asi