Piracy against American merchant shipping had not been a problem before 1776, when ships from the Thirteen Colonies were protected by British warships and treaties (nor was it a problem during the revolution, as the French Navy assumed the responsibility as part of the alliance treaty). Only after the U.S. achieved its independence did Barbary pirates begin capturing American ships and demanding ransom or tribute. Also, once the French Revolution started, the British Navy began intercepting American merchant ships suspected of trading with France, and France began intercepting American merchant ships suspected of trading with Great Britain. Defenseless, the American government could do little to resist. Even given these events there was great resistance in Congress to the formation of a naval force. Opponents asserted that payment of tribute to the Barbary states was a better solution than building a navy, which they argued would only lead to calls for a navy department, and the staff to operate it. This would then lead to more appropriations of funds, which would eventually spiral out of control, giving birth to a "self-feeding entity." Then, in 1793, a truce negotiated between Portugal and Algiers ended Portugal's blockade of the Strait of Gibraltar, freeing the Barbary pirates to roam the Atlantic. Within months, they had captured 11 American vessels and more than a hundred seamen.