This article critiques the assessment by exporting states of assurances that exported arms will not be misused by recipient states, with a focus on the Gaza conflict. First, the article develops a transferable framework for evaluating assurances. Building on the arms export obligations in the Geneva Conventions, and the implementation of those export obligations in the Arms Trade Treaty and EU Common Position, the article synthesises a due diligence test. It also draws on assurance assessment in another field where assurances are routinely given to overcome risk: when assurances attempt to address the risk of mistreatment to an expelled person implicating non-refoulement. The methodology for assurances assessments in risk prediction has been developed extensively in that area and closely resembles a similar approach emerging for arms exports. The article articulates the relevant criteria for assessing assurances when completing a due diligence risk assessment for arms exports and then applies that framework to the US arms exports in relation to the Gaza conflict. Under National Security Memorandum 20, the United States released a public report on its assurances assessment, offering a rare partial glimpse into the use of assurances in arms exports and an opportunity to examine whether assurances are being assessed in alignment with international practice. The result of the article is a clear practical checklist for lawful reliance on assurances and a tentative conclusion that the assessment by the US was not in compliance with international standards.