On Thursday evening, the White House published a document entitled, “National Security Memorandum on Safeguards and Accountability With Respect to Transferred Defense Articles and Defense Services” (NSM-20). The White House policy directive was prompted by (and supplanted) a measure Senator Chris Van Hollen (D-MD) had proposed in Congress. The latter would have come as an amendment to the supplemental military assistance for Israel. Given the broad executive branch discretion on the implementation of this directive and the unwillingness thus far of the State Department and White House to enforce existing legal and policy standards, there are reasons to be skeptical whether NSM-20 will substantively alter U.S. practice on arms transfers.

In December, Van Hollen, joined by over a dozen other democratic senators announced an amendment that largely restated existing U.S. requirements regarding arms transfers.  Procedurally, the amendment would have required the president to obtain assurances from recipients of U.S. defense articles and services that they will cooperate with U.S. humanitarian assistance efforts and provide reports to Congress on the use of U.S. defense articles and services, including whether they were used consistent with the law of war, U.S. law, and the Biden administration’s own Conventional Arms Transfer Policy.

Although the Van Hollen amendment did little more than recapitulate  existing U.S. law and policy and did not even mention Israel, much less condition U.S. military assistance to Israel, it stood little chance of receiving majority support in the Senate, given the challenging politics relating to Israel even within the democratic caucus itself. Nonetheless, in late December, the Biden administration engaged with Senator Van Hollen in an effort to incorporate elements of the legislation into executive branch policy. The result, NSM-20 imposes four primary requirements:

  1. The Secretary of State will obtain “credible and reliable” written assurances from recipients of U.S. defense articles funded with congressional appropriations that such arms will be used in accordance with international law, particularly the law of war.
  2. The Secretary of State will obtain “credible and reliable” written assurances from recipients of U.S. defense articles that they “will facilitate and not arbitrarily deny, restrict, or otherwise impede” the delivery of U.S. humanitarian assistance, in furtherance of supporting section 620I of the Foreign Assistance Act.
  3. If the Secretary of State or Secretary of Defense assess that the assurances have been called into question and should be revisited, they will report such assessment to the President along with recommended measures for remediation, including suspending further arms transfers.
  4. The Secretaries of State and Defense will issue annual reports to Congress on inter alia assurances, reports or allegations of potential law of war violations with covered U.S. defense articles and services, the civilian casualty mitigation practices of covered recipients, and the recipients’ cooperation with humanitarian assistance efforts.

The White House and Senator Van Hollen characterized the NSM-20 in starkly contrasting terms. The White House emphasized that the directive did not establish any “new standards” but instead “spell[ed] out publicly the existing standard by the international law” and further that with respect to Israel “we have not seen any violations of the standards so have no plans to restrict assistance at this time.” Indeed, the directive does not refer to Israel. For his part, Van Hollen lauded the directive as a “huge step forward in securing critical safeguards on the use” of U.S. arms. Meanwhile, detractors of the directive such as Senator Jim Risch (R-ID), the top Republican on the Senate Foreign Relations Committee, blasted the memorandum as “anti-Israel and calls into question the reliability of the administration.”

Both proponents and detractors of NSM-20 are overstating its likely significance.

Law of War Assurances

The U.S. government routinely makes use of law of war assurances in connection with support to foreign partners. As the Obama administration noted in a 2016 report, “[r]eceiving credible and reliable assurances that U.S. partners will comply with applicable international law, including the law of armed conflict, is an important measure that the United States military routinely employs in its partnered operations.” The formulation “credible and reliable” assurances is a term of art within the executive branch. “Credible” assurances are generally ones that are believable. To be “reliable” assurances must be provided by an official who can speak authoritatively on behalf of the foreign partner.

Although the U.S. government does not disclose the nature of all of the law of war assurances it receives and from whom it has received them, public reporting indicates such assurances have been sought in the past in conjunction with certain arms transfers. For example, in 2017 when the Trump administration resumed the sale of precision-guided munitions (PGM) to Saudi Arabia after President Obama had halted such transfers over concerns about civilian casualties in Yemen, the U.S. government sought assurances from Riyadh. These assurances reportedly included adherence to the law of war and additional measures to mitigate civilian casualties, such as the use of a no-strike list in Yemen.

Despite these assurances, the conduct of the Saudi-led air campaign did not improve and allegations of law of war violations persisted, perhaps most infamously with respect to Saudi Arabia’s bombing a school bus full of children with a U.S. precision guided munition. (The Saudis later gave conflicting accounts of why they targeted the vehicle.) This and other incidents continued to raise serious concerns about Saudi Arabia’s law of war compliance. Trump himself called the school bus bombing “a horror show” and candidly admitted that the Saudis “didn’t know how to use” U.S. weapons. Nonetheless, his administration persisted with further arms transfers to Saudi Arabia in the face of stiff congressional opposition due to consternation over civilian casualties.

Assurances and the Gaza conflict

Beyond the recent U.S. experience with Saudi Arabia, there are reasons to be particularly skeptical of the utility of seeking law of war assurances from Israel in connection with the conflict in Gaza. First and foremost, President Biden has so far refused to condition U.S. military assistance to Israel notwithstanding information that raises serious concerns regarding law of war compliance by the Israeli military, including with respect to target selection, proportionality, and the treatment of detainees. The strength of any assurances comes from the implied threat that there will be consequences if they are violated, which therefore necessitates conditioning U.S arms transfers on law of war compliance. As with the recent U.S. experience with Saudi Arabia, assurances received after the president has made clear that U.S. support is unconditional are unlikely to have teeth.

Indeed, even prior to the propagation of NSM-20, U.S. law and policy already imposed requirements related to law of war compliance on U.S arms transfers. Yet, the Biden administration appears to have failed to enforce these provisions of existing law and policy, including by not undertaking necessary analysis of Israel’s law of armed conflict track record in the Gaza conflict. Indeed, senior administration officials have disclaimed responsibility for making such judgments.  Having failed to undertake such legal assessments, it is therefore unsurprising that the White House claims not to have “seen any violations of the [law of war] standards.”

Nor is there much reason to think that the process of obtaining and assessing new law of war assurances from Israel will prompt any reconsideration of U.S. arms transfers. Despite the superficial rigor of new policy directive, there are a variety of ways the State Department may finesse the process for obtaining and assessing assurances to yield the desired policy outcome. This is particularly so given that the executive branch controls this process. (Eventual reports to Congress could, however, prompt pushback if they are perceived as whitewashing Israeli conduct.) The appraisal of both the initial credibility and reliability of the assurances as well as whether subsequent events call them into question is left to the Secretary of State, who (regardless of who occupies the position) is unlikely to come to a conclusion contrary to the White House’s policy preferences. Derogatory facts and analysis may not be given sufficient weight and State Department lawyers may resist reaching adverse legal conclusions regarding compliance. Indeed, some may do so in part because of their own potential legal liability. Certainly, the Department’s lawyers who reportedly have thus far not undertaken systematic assessments of Israel’s law of war compliance in Gaza seem unlikely to force the Secretary’s hand with respect to these assurances. It is all too easy to imagine Israel offering hollow assurances and the State Department readily accepting.

It therefore seems likely that with respect to the most politically sensitive covered recipients of U.S. arms, such as Israel, the law of war assurances process may be little more than a box-checking exercise.


As I wrote last November in a Foreign Affairs essay, “the U.S. government should be monitoring Israeli conduct in Gaza and determining whether Israel is using U.S.-origin weapons and intelligence consistent with the law of war. This is a basic step, seemingly required by existing law and policy, but it is one that the State Department is apparently not taking.” Given the failure of the State Department to undertake such assessments under pre-existing law and policy, it is hard to see how the adoption of a further, substantively duplicative policy will alter U.S. practice regarding arms transfers. NSM-20 may have solved the perceived political problem of a potentially divisive and embarrassing amendment raising the salience of Israel’s law of war track record in Congress. The new directive, however, seems likely to do little to either promote law of war compliance, or more importantly prompt the White House to use U.S. leverage to bring about a prompt end to the ruinous and destabilizing war in Gaza.

IMAGE: Sen. Chris Van Hollen (D-MD), talks to reporters with (L-R) Sen. Tina Smith (D-MN), Sen. Jeff Merkley (D-OR), Sen. Elizabeth Warren (D-MA), Sen. Tim Kaine (D-VA), Senate Minority Whip Richard Durbin (D-IL), Sen. Peter Welch (D-VT), Sen. Edward Markey (D-MA), Sen. Jon Ossoff (D-GA) and Sen. Mazie Hirono (D-HI) during a news conference at the U.S. Capitol to celebrate a new policy that demands recipients of foreign military aid adhere to international humanitarian law on February 9, 2024 in Washington, DC. (Photo by Chip Somodevilla/Getty Images)