The U.S. Navy came to the aid of American ships in April when they were attacked by pirates off the coast of Africa. Now, the shipowners are battling their rescuers, as Congress considers whether to require the Navy to protect American ships traversing high-risk waters.

Maritime companies have been lobbying lawmakers for such help for months, warning that the United States can’t afford to let its commercial ships be seen as easy targets by seafaring criminals. In June, the House passed language in a defense authorization bill ordering the military to provide protection. But Navy officials are pushing back, arguing that the ships should be responsible for their own safety — and, so far, the Senate seems to be listening.