As Israel reels from Hamas’ unprecedented October 7 assault and prepares for what could be a large-scale ground operation inside Gaza, the Biden administration has expressed its “ironclad support” for Israel and its determination to fulfill requests of assistance. Washington has already begun delivering additional military aid to Israel, reflecting a more than 70-years-long partnership underwritten by billions of dollars in arms transfers and security assistance.  

History of U.S. Military Aid to Israel

Israel is the largest cumulative recipient of U.S. military assistance since the Second World War, amounting to more than $124 billion over the past seven decades, not adjusted for inflation. In recent years, U.S. assistance to Israel has been outlined in a 10-year memoranda of understandings, the most recent of which was signed in 2016 and pledges $38 billion in military assistance between FY2019-FY2028.

Though U.S. security assistance to Israel takes many forms, the largest portion comes through Foreign Military Financing (FMF), which are grants to support the purchase of U.S. defense articles and services.¹FMF can also be provided as a direct loan to be repaid by the recipient. The current MOU commits the United States to $3.3 billion in annual FMF to Israel, the largest routine FMF package the United States provides on an yearly basis and which alone represents approximately 16% of Israel’s defense budget.

Israel also has unique privileges in how it uses its FMF funding. Israel is eligible for “Cash Flow Financing,” which allows it to use FMF to finance multiyear purchase without having to pay for acquisitions entirely up-front. Additionally, Israel has also been permitted to spend FMF appropriations on Israeli weaponry, a practice that is being phased out in the current MOU but has historically pumped hundreds of millions of U.S. dollars into the Israeli defense industry. Israel is also permitted to use FMF to purchase armaments directly from U.S. manufacturers using the direct commercial sales process, and also enjoys expedited Congressional review periods for its arms packages.

In addition to FMF, Israel also receives U.S. assistance for joint missile defense development procurement. The current MOU pledges $5 billion over the life of the arrangement for various missile defense programs that are often developed or produced with U.S. firms. This includes investments in Israel’s much vaulted Iron Dome short range air defense system, as well as other longer-range platforms like Arrow II, Arrow III, and David’s Sling. Between FY2006 and FY2023, the United States has appropriated more than $8.6 billion for various U.S-Israeli missile defense programs.

Beyond the direct support the United States provides to Israel, U.S. regional security cooperation is also aimed at maintaining Israel’s “qualitative military edge,” (QME) a term which refers to the technical sophistication of Israel’s defense equipment vis-à-vis its neighbors. Although originally an informal commitment, successive administrations and Congressional actions have codified U.S. support for Israel’s QME, including measures like allowing Israel first regional access to U.S. defense technology or more advanced versions of systems provided to other regional partners.

U.S. Assistance in Light of the Current Crisis

In the immediate aftermath of Hamas’ assault, Israel quickly requested additional security assistance from the United States, which Washington has said is already arriving in country. Specifics surrounding Israeli request are not clear but are said to include various munitions and air defense supplies.

To meet Israeli requests, President Biden is likely to turn to his drawdown authority, which allows the administration to transfer materiel from its own stockpiles to partner countries. The White House has leaned heavily on drawdowns to sustain Ukraine’s war effort, which has dramatically depleted supplies of key capabilities in the U.S. arsenal. This is unlikely to impact the immediate availability of certain weapons systems – including air to ground munitions or interceptors for Israel’s Iron Dome system – which are not currently fielded in Ukraine. However, for other armaments, including artillery ammunition, competing demands on already strained U.S. supplies may prove challenging.

But the President’s drawdown authority is capped, which underscores the administration efforts to encourage supplemental funding from Congress. Though details are scarce, early reports suggest the administration is nearing agreement with Congressional leaders on a $2 billion supplemental package to support replenishment of Israeli military stocks.

While the United States has said that planes carrying supplies to Israel “have already taken off” and reports suggest assistance from outside the country has begun to arrive, the U.S. also has pre-positioned stocks inside the country that it could allow the Israelis to access. These “War Reserve Stocks” reportedly included missiles, armored vehicles, and artillery ammunition.   Over the past several decades, Israel has requested access to the stockpile on at least two occasions, including during its 2006 war against Hezbollah and its 2014 military operation in Gaza. Though the state of the stockpile is unknown, and the Biden administration has reportedly drawn from the reserves to provide support to Ukraine, it may be a source of additional surge assistance for Israel. Additionally, the White House has pressed U.S. defense industries to expedite existing Israeli orders for arms. Reports indicate that Boeing has already accelerated the delivery of its small diameter bombs originally purchased by Israel in 2021. But the request come at a time of increasing strain on the defense industrial base, which could hamper efforts to ramp up deliveries to Israel.