The U.S. sale of advanced F-16 fighter jets to Taiwan is looking more likely than ever. That is likely to raise tensions in the budding military-to-military relationship being built by the U.S. and China, shortly after the Chinese defense minister visited major U.S. military institutions earlier this month.

The U.S. House of Representatives voted to approve the sale of 66 advanced F-16C/D fighter jets to Taiwan last Friday. But the amendment placed into the Defense Authorization Bill by Rep. Kay Granger, R-Texas, to include the jets does not provide a timeline for when the sales would take place.

A final decision on the bill won't happen until the Senate votes to approve its own version, and until it is finally signed by President Barack Obama. In the meantime, domestic political bickering in the U.S. and Sino-U.S. diplomatic squabbling will continue over the significance of the deal.

Another Texan, Republican Sen. John Cornyn, has been a staunch advocate for F-16 sales to the island. Cornyn, who sits on the Senate's Armed Services Committee, had held up the Obama administration's nomination of Mark Lippert to serve as the new assistant secretary of defense for Asian and Pacific security affairs, conditional upon the administration's consideration of F-16 sales to Taiwan.

The White House subsequently said it would be open to proposals on a deal.

Political pressures on Obama to appear strong against China may in fact push him to follow through with the plan. The deal is widely seen in the U.S. military community as a means to shore up Taiwan to provide more balance against China, which has modernized and expanded its forces dramatically in recent years. It may also be politically damaging for the president to back down on arms sales during an election year when he has received criticism from Republican candidates for being acquiescent to Beijing.

In the past, China has broken off military-to-military meetings and exchanges with the U.S. over Taiwan arms sales. But Taiwanese-Mainland China politics are also at a particularly complex stage. It is uncertain how Beijing will react to the deal if eventually passed, especially since it has worked of late to improve relations with Taipei.

Chiang Kai-shek's Nationalists (the Kuomintang or Guomindang party), which governed the Republic of China, fled to Taiwan in 1949 after being defeated by the Communists. The Communists established rule over the mainland as the People's Republic of China at the same time. Throughout the Cold War, both governments claimed they were the sole legitimate representative of China. However, democratization on Taiwan since the 1990s has given increasing voice to an indigenous independence movement. In order to oppose any moves by Taiwan to officially declare independence, Beijing says it reserves the right to use military force.

Since the election of Nationalist President Ma Ying-jeou on Taiwan in 2008, tensions between the mainland and the island have eased tremendously. The recently re-elected Ma comes after two previous anti-Beijing, pro-independence presidents and has labored over his first term to open the two sides to regular air, sea, and mail transportation and favorable trading and investment policies.

But China remains fearful of Taiwan's independence advocates, and Taiwan's dynamic democratic processes mean that large uncertainties remain over the future. Although Ma has improved relations between the two sides, he has resisted signing a formal peace agreement with China and is a proponent of improving Taiwan's military capabilities. The U.S. says it opposes any unilateral decisions by either side to change the status quo (either military action or independence referendums), and past agreements obligate it to protect Taiwan from mainland attack.

China will officially spend $106 billion on defense over the next year, though analysts in the U.S. say the real figure is much higher. Taiwan's spending in the past has generally been about a tenth of that number. Over the past years China has arrayed powerful forces against the island, some capable of resisting or even possiblly defeating U.S. forces, including more than 1,400 short and intermediate range missiles and hundreds of aircraft. The hi-tech F-16 C/D, built by major U.S. defense contractor General Dynamics, would be a step towards alleviating that disparity, though few experts think Taiwan could really outlast a real assault from the mainland even with the new jets, unless there was direct U.S. involvement.

Over the past three years, the U.S. has already sold $18.3 billion worth of weapons to Taiwan, although past deals did not include the new sophisticated jets, only upgrades to a previous version already in Taiwan's inventory. China regularly protested past sales, but is especially vehement against U.S. sales of advanced aircraft.

The Foreign Ministry in China announced on Monday its displeasure at the possibility of the new arms deal coming to fruition . China is resolutely opposed, said spokesman Hong Lei.

China said selling weapons to Taiwan goes against the One-China Policy and common diplomatic agreements signed by both parties. It severely interferes with Chinese internal affairs, said Lei.