Speculating: Bush considers Southeast Asia a key front in his war. He has been trying to further infiltrate that area for a long time. Thus we see 15,000 Americans on board but few flying missions or going ashore to help.
The United States is trying for control of the Strait of Malacca. US Defence Secretary Donald Rumsfeld said during a visit to Singapore that he hoped to have US troops fighting terrorism in Southeast Asia "pretty soon". His comments fuelled speculation that the United States wants to deploy US forces in the Strait of Malacca, the narrow and busy shipping lane straddled by Malaysia, Indonesia and Singapore that is seen as a likely terrorist target. More than one million tonnes of oil a year -- well over 80 percent of China's imports -- are shipped through the narrow strait. #msg-3404130
Reference: The Pentagon sent the aircraft carrier Abraham Lincoln and several other ships to the Indian Ocean, though military officials said the vessels and crews had not yet been assigned specific missions. About 15,000 Americans are on board. Only a small portion of them would be expected to fly missions or go ashore. #msg-4952165
On the campaign against terrorism, the Australia and the US agreed that South East Asia was a key front, affirming the importance of working with regional governments against a common threat. #msg-3542419