NAIROBI - The US military is once again tangling with pirates, intervening in waters off Somalia twice last week to help ships seized by hijackers and bringing to mind another century's battles off the coasts of Africa.
Pirates may have swapped muskets and the Jolly Roger for AK-47s and satellite phones, but the root causes of piracy are unchanged from when Thomas Jefferson contemplated how to handle attacks on American merchant ships two centuries ago.
"Instead of swinging from ropes, now it's boarding vessels with automatic weapons," said Cyrus Mody, a senior analyst at the International Maritime Bureau, which tracks pirate attacks.
The Barbary pirates of Jefferson's day took advantage of vast, unpatrolled African territory and leaders who encouraged criminality to prey on American merchant ships.
Today, impoverished and weak governments in Africa have few resources to police on land, much less patrol territorial waters that can stretch a dozen or more miles into the Indian or Atlantic oceans. The lack of security near major shipping lanes has created fertile ground for hijackers, and the US Navy came to the aid of hijacked vessels from North Korea and Japan last week in the waters off Somalia.
"This is a very serious security problem on the African coast. These are not pirates who will remind you of Johnny Depp," Assistant Secretary of State Christopher Hill said Friday in Seoul.
Latter-day pirates frequently travel in open skiffs with outboard engines, often working with larger mother ships that tow them far out to sea, Mody said.
Armed with heavy weaponry, satellite navigational, and communications equipment and an intimate knowledge of local waters, they clamber aboard commercial vessels with ladders and grappling hooks.
In Somalia, some pirates are linked to the clans that have carved the country into armed fiefdoms. They have seized merchant ships, aid vessels, and even a cruise ship. The motives aren't always to loot or seek ransom.
Andrew Mwangura, a Kenya-based program coordinator of the Seafarers Assistance Program, which monitors pirate activity, said a recent attack off Somalia appeared to have been a local ship agent's way of resolving a financial dispute.
Pirate attacks rose dramatically off Somalia in the first nine months of the year, with 26 reported cases, up from eight during the same period last year, according to International Maritime Bureau figures. Nigeria also suffered 26 attacks so far this year, up from nine previously, the bureau said.
Almost all of southern Nigeria, where Africa's largest oil producer pumps its crude, is a vast wetland of creeks and swamps.
Militants attack government and commercial vessels, destroying property and kidnapping foreign oil workers, more than 150 this year alone. While some claim to be pursuing political goals, they are frequently pirates, with many of their attacks included in International Maritime Bureau data.
Captain Henry Babalola, a spokesman for the Nigerian navy, said Nigeria's coast is too long to patrol effectively; the two oil-rich states where most of the attacks occur have only 15 navy patrol vessels.
Maritime pirate attacks worldwide rose 14 percent in the first nine months of 2007 from a year earlier, with Somalia and Nigeria among the biggest increases. The total economic cost is incalculable, the maritime bureau said.
The bureau reported 198 attacks on ships between January and September, up from 174 in the same period in 2006. It said 15 vessels were hijacked, 63 crew kidnapped, and three killed.
The US military intervention last week to help the North Korean tanker came after its crew managed to overpower the hijackers and retake the vessel in a bloody fight.