Piracy is a robbery committed at sea, or sometimes on the shore, by an agent without a commission from a sovereign nation. The Golden Age of Piracy occurred mostly in the Caribbean, the American coast, the Indian Ocean, and the western coast of Africa. As British imperialism spread across Europe it brought about many drastic structural changes due to which many sailors and privateers found themselves unemployed. Factors contributing to piracy included the rise in quantities of valuable cargoes being shipped to Europe over vast ocean areas, the weakness of European navies in peacetime, the training and experience that many sailors had gained as conscripts in European navies (particularly the Royal Navy), and the weakness of European government in overseas colonies.
Seaborne piracy against transport vessels remains a significant issue (with estimated worldwide losses of US$13 to $16 billion per year), particularly in the waters between the Pacific and Indian Oceans, off the coast of Somalia, and in the Strait of Malacca and Singapore, which are used by over 50,000 commercial ships a year. A recent surge in piracy off the Somali coast spurred a multi-national effort led by the United States to patrol the waters near the Horn of Africa to combat piracy. While boats off the coasts of North Africa and the Mediterranean are still assailed by pirates, the Royal Navy and the U.S. Coast Guard have nearly eradicated piracy in U.S. waters and the Caribbean.