On September 28th, the Trump administration announced the decision to temporarily waive the Jones Act for Puerto Rico, effective for 10 days. “It will go into effect immediately,” according to White House press secretary Sarah Sanders.

In the wake of Hurricane Maria, Puerto Rico is in desperate need of food, medicine, clothing and other supplies, and suspending the Jones Act will lift significant barriers to relief efforts.

The Jones Act, passed in 1920, requires all goods shipped between ports in the United States to be built, owned, and operated by Americans. The Act was intended to encourage growth in the U.S.maritime industry and establish American control over local commercial shipping. Opponents argue that these restrictions unfairly increase the cost of goods shipped to non-mainland states or territories and restrict exports from those ports, but defenders claim the law protects American manufacturers form foreign competition and strengthens national security—the original purpose of the bill.

Amidst criticism of the administration’s failure to respond to the devastation in Puerto Rico, several members of Congress and government officials expressed support for the waiver, including Defense Secretary Jim Mattis. Senator John McCain (R-AZ), a long-time advocate for repealing the Jones Act, cited the need for “an expedient and functional transportation system” to respond to the “worsening humanitarian crisis” in his plea for suspension. The final decision was made by Elaine Duke, the acting head of Homeland Security, who also granted a temporary waiver following Hurricanes Harvey and Irma to expedite the transport of petroleum.