The Obama administration may have finally lost its patience with China’s salami-slicing in the East and South China Seas. Remarks over the past few weeks from administration officials show a tougher line and may foreshadow “red lines” to ward off further Chinese encroachments. These developments may show a White House increasingly ready to abandon a previous policy of forbearance toward China. It could also mean an impending tilt away from explicit U.S. neutrality toward the many territorial disputes in both seas. Given China’s stepped-up assertiveness, the drawing of red lines seems inevitable. The next question though is whether the U.S. will be able to back up these red lines with convincing military power. China’s military modernization program has long anticipated this move, leaving the answer anything but clear.

Heretofore, the U.S. has pursued a policy of forbearance with China, with the hope that by going out its way to show respect for China’s emerging great power status, Washington would avoid a ruinous security competition. In remarks at a Washington, D.C. think-tank in January 2014, Kurt Campbell, the U.S. Assistant Secretary of State for East Asian and Pacific Affairs during President Obama’s first term, explained the administration’s theory. According to Campbell, previous historical examples of rising powers clashing with established powers were typically the result of insufficient respect being paid to the rising power (see 55:00 in). In the case of China, Campbell explained that the Obama administration would not repeat that mistake. In her first speech on Asia as President Obama’s new National Security Advisor, Susan Rice mimicked China’s call for “a new model of major power relations” between the U.S. and China and then recited a long list of issues on which she hoped the two countries would cooperate. Rice made no mention of China’s 2012 takeover of Scarborough Reef from the Philippines or China’s establishment that same year of a government headquarters and military garrison on Woody Island in the Paracel island group, which China seized from Vietnam in 1974. Three days after Rice’s speech, China declared an air defense identification zone (ADIZ) over the East China Sea.

In alignment with the China forbearance policy is the U.S. declaration of neutrality regarding the long list of territorial disputes over islands, rocks, and reefs in the East and South China Seas. In a speech on June 1, 2013 to the Shangri-la Dialogue conference of regional defense ministers in Singapore, U.S. defense secretary Chuck Hagel repeated America’s long-standing position that, “we do not take a position on the question of sovereignty in these cases,” only that the U.S. opposes the use of coercion to alter the status quo. This U.S. position has served two purposes. It has allowed the U.S. to avoid writing a blank check to a hypothetically reckless ally, one that could theoretically entrap the U.S. in an unwanted conflict. Second, it supported the forbearance policy by providing U.S. policymakers with a convenient talking point whenever territorial squabbles in the region flared up.

The policies of forbearance and neutrality could not survive if China continued its salami-slicing march across the region. China’s declaration of the East China Sea ADIZ, its continued siege of a tiny Filipino marine garrison on Ayungin Island in the Spratly chain (emotionally described in a long New York Times Magazine essay), and China’s January 2014 edict requiring fishermen in the South China Sea (including in waters far beyond China’s exclusive economic zone) to obtain fishing permits from China may have finally convinced Obama administration officials that the forbearance policy was a failure. Perhaps most worrying for Washington is the nationalistic reaction to these developments in Japan, which is a sign of declining confidence in the U.S. security guarantee and which threatens a loss of U.S. control over events in the region.

A rapid series of recent pronouncements by Obama administration officials may indicate that a new U.S. policy is now emerging. The stiffer tone first appeared on January 31, 2014, when Evan Medeiros, the senior director for Asian affairs on the U.S. National Security Council (NSC), rejected the legitimacy of China’s East China Sea ADIZ and warned that if China declared an ADIZ over the South China Sea, “that would result in changes in [U.S.] presence and military posture in the region.” In congressional testimony on February 5th, Daniel Russel, Kurt Campbell’s replacement as Assistant Secretary of State for East Asia and Pacific Affairs, specifically and publicly rejected China’s use of its “nine-dash line” as a legitimate basis for China’s territorial claim in the South China Sea, the first time a senior U.S. official has explicitly done so. Also a first for a senior U.S. official was Russel’s cataloging of China’s serial encroachments against Philippine and Vietnamese interests and territorial claims in recent years. On February 13, Admiral Jonathan Greenert, the U.S. Chief of Naval Operations, told an audience at the Philippine National Defense College that the United States would come to the aid of the Philippines in the case of a hypothetical conflict with China over disputed claims in the South China Sea. Finally, on a February 17th visit to Indonesia, U.S. Secretary of State John Kerry similarly listed China’s recent provocations and called for the resolution of territorial claims based on existing international law, another rebuke to China’s nine-dash line claim in the South China Sea.

A tougher line against China may signal the end of restrained U.S. forbearance. Under the previous policy, the administration hoped that a welcoming and nonthreatening approach would induce China to accept the international system that has benefited China so greatly over the past three decades. Instead, China’s behavior since 2008 seems to have interpreted U.S. restraint as weakness, an impression further catalyzed in China by the 2008 financial crisis, the subsequent struggles of the U.S. economy, and the budget wars in Washington that have shrunk projected U.S. defense spending. Having not received the response from Beijing that they had hoped for, the White House seems to have concluded that it will need a tougher approach.

But if the U.S. draws red lines in the South China Sea, will it be able to back them up?

The “Asia Rebalance” strategy, announced more than two years ago, and a U.S. pledge to station sixty percent of its naval and air power in the Asia-Pacific theater, has not deterred China’s continued salami-slicing. As the Obama administration was reminded in Syria, policymakers should not draw red lines unless they can convince the adversary that he has no chance to successfully challenge them.

NSC official Evan Medeiros’s pledge to further bolster U.S. military forces in the region should China impose an ADIZ over the South China Sea could be an empty threat—the U.S. has little, if any, reserve military power to permanently commit to the region. For example, the demand for the U.S. Navy’s aircraft carrier strike groups already exceeds their availability, with standard deployment times expected to rise from six months to eight or more to cope with current requests by U.S. regional commanders. Demand for attack submarines similarly exceeds availability, a condition that is expected to worsen in the future as the U.S. submarine fleet shrinks.

Washington could increase the military’s allocation to the Pacific beyond sixty percent by stripping resources from the Middle East and elsewhere. But China’s access-denial military strategy, which employs China’s rapidly expanding force of land-based missiles, aircraft, and submarines against U.S. bases and surface ships in the Western Pacific, makes this a risky idea and one that could perversely increase the region’s military instability. The U.S. military’s air and naval power is excessively concentrated in relatively short-range aircraft and missiles. Positioning even more of these forces at forward bases that are already vulnerable to China’s missiles will increase the risk to U.S. forces and may do little to deter Chinese behavior. That would be a stunning outcome to U.S. policymakers who have long counted on possessing escalation dominance during crises.

It was inevitable that China’s continued salami-slicing in the East and South China Seas would meet resistance. China’s declaration of an ADIZ over the East China Sea last November along with subsequent actions has apparently brought the Obama administration’s policy of restrained forbearance toward China to an end. American red lines in the South China Sea may come next. However, China’s two-decade military modernization program, with its emphasis on missiles and submarines, has anticipated such steps. With a shortage of long-range striking power and other tools to offset China’s access-denial strategy, the United States will have to take some unfamiliar risks to back up the coming red lines. That the U.S. military will soon face such risks is an indictment of the Pentagon’s strategy and procurement policies over the past decade and more. Until those are fixed, U.S. policymakers will have to hope that American naval and air power still retains its awesome reputation, and that looming U.S. red lines will thus go unchallenged. But how long that reputation will hold up in East Asia remains to be seen.

Robert Haddick is an independent contractor at U.S. Special Operations Command. He writes here in a personal capacity. In September 2014, U.S. Naval Institute Press will publish “Fire on the Water: China, America, and the Future of the Pacific,” Haddick’s book on the rise of China’s military power and U.S. strategy in East Asia.