Panetta explains Pentagon's 'pivot' toward Asia SINGAPORE -- As the U.S. seeks to reassert its role as a Pacific power after a decade of distant ground wars, the Obama administration has run into a problem: It's hard to convince allies and rivals that the enhanced military commitment to Asia is sufficiently serious. The Pentagon will replace older warships and add eight new ships to the Pacific fleet by 2020, but it plans only modest increases in other U.S. forces to a vast region that is increasingly anxious about China's growing political and military clout and North Korea's nuclear arsenal. In a policy speech Saturday to an annual gathering of Asian defense officials, U.S. Secretary of Defense Leon E. Panetta sought to reassure allies that the "pivot" to the western Pacific and East Asia that President Obama promised during a visit to the region in November represented a substantial new effort, and not political spin. Panetta urged his counterparts not to focus on the figures alone, but to look at America's renewed commitment to protecting some of the world's most vital shipping lanes. "I would encourage you to look at the increasing technological capabilities of our forces as much as their numbers in judging the full measure of our security presence and the measure of our commitment," Panetta said at the news conference. He said advanced new weapons systems -- including F-35 fighter jets now under development and fast-attack Virginia-class submarines -- will provide "our forces with freedom of maneuver in areas in which our access and freedom of action may be threatened." The U.S. military largely withdrew from Southeast Asia after the Vietnam War ended in the mid-1970s and major U.S. Navy and Air Force bases closed in the Philippines in the early 1990s. The return to the region is still small-scale by those standards. As part of the plan, the Navy will base four new lightly armed ships in Singapore. They will operate in the Strait of Malacca, a strategic choke point for global transit of oil and trade, and the energy-rich South China Sea, where territorial jostling between China and other countries have raised tensions. Patrick M. Cronin, an Asia security expert at the Center for a New American Security, a Washington-based think tank, said Japan and other longtime U.S. allies worry that possible defense cuts will make it harder for Washington to play the stepped-up security role that Panetta described. "It's complicated when the Chinese see [the pivot] as more real than your allies and partners," Cronin said. Allies always want more reassurance. U.S. officials say China has moved to counter America's military edge in the Pacific and has developed anti-ship missiles, is developing an advanced fighter and is planning to launch its first aircraft carrier. But Beijing remains far behind Washington in its ability to project military power. Washington's refocus on the region is carefully calibrated not to upset that balance, or to alarm deficit hawks in Congress. With major cuts expected in the U.S. defense budget over the next decade, the Pentagon plans to increase the Pacific fleet from 50 warships to 58, according to two Pentagon officials who discussed the plans on condition of anonymity. In addition, Panetta said that more than 40 Navy ships in the Pacific would be replaced with "more capable and technologically advanced ships" over the next five years. But the number of warships "forward deployed" at any one time -- operating in Asian waters rather than moored in San Diego or other U.S. ports -- will grow by only four, from 23 to 27, by 2020. The reason: It is far less expensive to base troops, ships and planes in U.S. ports than abroad. The six aircraft carriers now assigned to the Pacific will drop to five later this year. An additional carrier, now under construction, is scheduled to enter the fleet in 2014, returning the number to six. Several hundred Marines have begun rotating into northern Australia on a training mission, and the force may grow to as many as 2,000 by 2016. But U.S. troop levels in South Korea, Japan and elsewhere in the region are likely to remain flat. Panetta, who has been invited to visit China later this year, emphasized that the new strategy is not aimed at confronting China, whose defense minister and other top officials skipped this year's conference after attending last year. Some view the increased emphasis by the United States on Asia-Pacific as some kind of challenge to China. I strongly reject that view," Panetta said. The "increased U.S. involvement in this region will benefit China as it advances our shared security and prosperity." Yet after he leaves Singapore, Panetta will visit Vietnam and India, two countries with uneasy relations with China, in what U.S. officials describe as an effort to deepen U.S. military ties with both allies. Vietnam says that Chinese ships sabotaged oil explorations in its waters twice last year by deliberately cutting undersea cables, charges that China denied. And China has competing territorial claims in the South China Sea with Malaysia and Brunei. Some Pentagon officials worry that the new U.S. effort may embolden the Philippines and other countries with defense treaties with Washington to be more assertive in disputes with China over seabeds believed to hold large oil and gas deposits, possibly sparking confrontations that U.S. officials want to avoid. Panetta said that the U.S. is "paying close attention" to a standoff between Chinese and Philippine ships on Scarborough Shoal, a valuable fishing ground in the South China Sea that both countries have claimed. The area is known in China as Huangyan Island. "We do not take sides when it comes to the competing territorial claims, but we do want this dispute resolved peacefully and in a manner consistent with international law," Panetta said.