U.S. ships are returning to the Red Sea following promises from Yemen’s Houthi rebels to abstain from attacks on American and British vessels. The pledge, which comes after more than a year of shipping traffic disruption on a major international trade route,

British and American ships are tentatively returning to the Red Sea after Yemen’s Houthi rebels vowed to hold off attacks on vessels linked to both nations, a sign that traffic on one of the world’s main trade routes could normalize after more than a year of disruption.

Shipping companies expressed caution about using the shorter route between Asia and Europe that many ships have avoided for more than a year.