In a potential groundbreaking move, the United States is anticipated to announce the blocking of military aid to an Israeli army unit due to gross human rights abuses in the Israeli-occupied West Bank. This would be the first time in their long-standing alliance that the US invokes the Leahy law against an Israeli military unit.

The strained relationship between the US and Israel has been further exacerbated by civilian casualties and suffering in Israel's conflict with Hamas in Gaza. The Leahy law, named after former Vermont Senator Patrick Leahy, was introduced in the 1990s as a means for the US to withhold military aid and training from foreign security units involved in extrajudicial killings, rapes, torture, and other blatant human rights violations.

Under the law, if the State Department identifies credible evidence of gross abuses committed by a military unit, aid must be automatically cut off. The same principle applies to Defense Department training of foreign militaries. While other US laws address different circumstances that would call for cutting military support, the Leahy law specifically targets human rights abuses.

Critics, including rights groups, have long accused US administrations, including President Joe Biden's, of avoiding rigorous investigations into allegations of Israeli military killings and other abuses against Palestinians, in order to sidestep triggering laws aimed at conditioning military aid on lawful behavior. Israel maintains that it investigates abuses and holds offenders accountable through its court system.

Interestingly, the US has previously invoked the Leahy law concerning security assistance to countries in regions such as the former Soviet Union, Central and South America, and Africa. However, it is uncommon to see it applied to strategically significant US allies. For example, in 2022, the US found sufficient evidence of abuses warranting invoking the Leahy law in Azerbaijan, Kyrgyzstan, Mexico, and Saint Lucia.

There is the option for the administration to notify Congress about Leahy law incidents in classified settings, thus avoiding potential embarrassment to important partners. According to Sarah Elaine Harrison, a former Defense Department attorney who worked on Leahy law issues, no previous US government has utilized the legislation against Israel. She also highlights a 2021 treaty in which Israel agreed not to share US military aid with any unit that the US had deemed credibly guilty of gross human rights abuses.

One potential way for an offender to be exempt from the Leahy law is if the Secretary of State determines that the government in question is taking effective measures to bring the offenders within the targeted unit to justice.

Despite these developments, the US still maintains substantial funding and arms assistance to Israel. This includes a recently proposed $26 billion package to support Israel's defense and address the growing humanitarian crisis in Gaza. The Senate is expected to pass the package this week, with President Biden expressing his intention to sign it.

As US-Israel relations navigate these challenging moments, the outcome of the expected blocking of military aid to the specific Israeli army unit could have significant repercussions for the future of the partnership between the two nations.