While piracy rages unabated in the Gulf of Aden and off the coast of Somalia, attacks on the other side of the Indian Ocean in the Straits of Malacca and the South China Sea have steadily dwindled largely because Southeast Asian nations have banded together to fight that scourge of the sea.

During the first quarter of 2009, attacks in Southeast Asian waters were down to nine, compared with 41 during the same period of 2004, according to the International Maritime Bureau. The IMB, with headquarters in Kuala Lumpur, said pirates attacked 63 ships off Somalia or in the Gulf of Aden in this period. The best known, of course, was the Maersk Alabama captained by Richard Phillips.

The director of the IMB, Pottengal Mukundan, said this surge of piracy off Somalia was worrisome "principally because attacks have taken place many hundreds of miles off the country's coastline. The problem of Somali piracy has now spilled over to neighboring countries, threatening trade routes into their ports."

In contrast, only one incident was reported during this quarter in the Malacca Strait. A seagoing Singaporean tug towing a barge was boarded by 12 pirates with rifles who stole navigation and communications equipment, plus money and personal belongings of the crew. The pirates kidnapped the tug's master and first officer and fled. The two were later freed after the owner paid an unspecified ransom.

The IMB, in its quarterly report, said: "The littoral states should be complimented for their continued efforts in maintaining and securing the safety of this strategic trade route. This has been the result of increased vigilance and patrolling by the littoral states and the continued precautionary measures on board ships."

The differences between Southeast Asia and Somalia are striking. Governments in Indonesia, Singapore, Malaysia and Vietnam are operative and can crack down on pirates; Somalia is a lawless, failed state. Nations around the South China Sea have begun to overcome issues of sovereignty to start working together even though they are jealous of the independence from European colonial powers gained after World War II.

Geography favors Southeast Asia as the South China Sea is a big lake and the straits in and out are easier to control than the wide Indian Ocean. Joint "eyes in the sky" patrols, coordinated naval patrols, sharing of intelligence, and command centers that communicate with each other have helped. So has getting agencies within a government to work together. Indonesia, for instance, has 13 agencies in maritime security.

Not all is well, however. Some pirate attacks go unreported because ship owners find it cheaper to suffer the loss of cargo and equipment, and even paying ransom, than to pay higher insurance premiums. Nor do they want to pay for arming and training merchant seamen to ward off pirates or to hire guards to defend their ships.

Even so, the U.S. has helped the Southeast Asians protect the vital sea lanes through which pass more ships every year than through the Panama and Suez Canals combined. For the U.S. Navy, which has been shifting its weight from the Atlantic into the Pacific and Indian Oceans, this passage is essential to sailing warships between the two oceans.

The U.S. has funded radar stations, command and communication centers, and patrol boats, plus encouraging Southeast Asians to work together. When Adm. William Fallon, then commanding U.S. Forces in the Pacific, was in Indonesia to discuss piracy and terror three years ago, an Indonesia officer told him: "This is our problem and, with our neighbors in Singapore and Malaysia, we can take care of it."

Fallon was clearly pleased. "It's your neighborhood," he replied, "and you should do it yourselves. If we can help, please let me know."

Richard Halloran, formerly with The New York Times as a correspondent in Asia and in Washington, is a writer in Honolulu.