On June 26, Senator Corker, Chairman of the Senate Foreign Relations Committee (SFRC), informed Secretary Tillerson that, in light of the current diplomatic stalemate between Saudi Arabia, the United Arab Emirates, and Qatar, the SFRC would not “provide any further clearances during the informal review period on sales of lethal military equipment” to the six members of the Cooperation Council for the Arab States of the Gulf, or GCC — Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. Chairman Corker indicated that this policy would remain in place until the SFRC has “a better understand of the path to resolve the current dispute and reunify the GCC.” Of course, many have urged the United States to halt arms sales to Saudi Arabia for other reasons, in particular Saudi Arabia’s failure to comply with basic principles of international humanitarian law that have resulted in excessive civilian casualties in Saudi Arabia’s ongoing armed conflict in Yemen.

Does Chairman Corker’s letter signal an end to arms sales to Saudi Arabia and other GCC countries for the foreseeable future? Not necessarily.

Under Section 36 of the Arms Export Control Act (AECA), Congress generally must be notified at least 30 calendar days before the Executive Branch can take the final steps to finalize foreign arms sales above certain dollar value thresholds. The notification periods differ slightly for sales to NATO member countries, Japan, Australia, South Korea, Israel, and New Zealand.

In addition to formal notification under the AECA, the Executive Branch (through the Department of State) typically informally notifies the Congressional committees of jurisdiction (the SFRC and the House Foreign Affairs Committee) 20 to 40 days in advance of the AECA statutory notification period of any potential arms sale that would trigger formal notification under Section 36 of the AECA. In general, the Executive Branch will not proceed to formal notification under the AECA (and, therefore, to arms sales) without receiving concurrence from the key Congressional committees during the informal notification period.

Thus, if the SFRC stops providing informal concurrence for sales to the GCC countries, the Executive Branch normally would not proceed to formal notification for these sales and the sales would not be consummated. However, this practice of an informal notification and clearance process has developed in the interest of comity between the Executive and Legislative branches, and it is not required by law.

As a legal matter, Congress does have the ability to restrict arms sale to foreign governments, but this action rarely has been applied, which is not apparent from Chairman Corker’s letter. In general, after complying with licensing, notification, and other legal requirements in the AECA and other law, the Executive Branch may proceed with foreign arms sales unless Congress passes legislation that would stop the sale.

Congress has some history of attempting to pass legislation to block arms sales to Saudi Arabia, with at least some success. In 1981 and 1986, Congressional attempts to pass laws to block arms sales to Saudi Arabia failed, but only after President Reagan made commitments to modify the relevant sales proposals to account for concerns expressed by Congress. In addition, Congress has other tools at its disposal, including its oversight and appropriations responsibilities, to express its displeasure with actions by the Executive Branch.

Notwithstanding Chairman Corker’s letter, it remains to be seen whether the Trump Administration will continue with arms sales to Saudi Arabia and force Congress to consider taking legislative or other action on future sales.