Coverage of the South China Sea territorial dispute has tended to paint the story as that of a giant China flexing its muscle over a handful of smaller Southeast Asian states. But while China’s increasingly assertive behavior shows its willingness to exploit the weaknesses of other claimants, the picture is not as simple as it is often portrayed. Vietnam and the Philippines are pushing back against China, and many countries are stoking tensions in the sea. Together, their actions leave plenty of room for open conflict to break out.

Vietnam and the Philippines are no strangers to confronting China over the South China Sea. Vietnam and China fought two wars in the 1970s and 1980s over the Paracels, while China occupied a Philippine-claimed reef in the mid-1990s in the Spratlys. Tensions have run high again in recent years, driven by resource and strategic interests.

Beijing is more determined than ever to ensure that its Southeast Asia rivals do not come between it and its territorial claims. In the face of Beijing’s growing confidence, Hanoi and Manila are actively enlisting the aid of ASEAN and the United States.

Vietnam had some early success. Hanoi deftly outmaneuvered China, much to Beijing’s embarrassment, by championing the sovereignty issue on ASEAN’s agenda during its chairmanship of the organization in 2010. Its efforts culminated in U.S. Secretary of State Hillary Clinton’s landmark speech that declared that the South China Sea was a U.S. “national interest.” The phrase was a rude awakening for China and, according to a Vietnamese diplomat, was a major reason that Beijing started taking Hanoi more seriously.

However, Hanoi and Manila’s efforts are now failing to convince China to tread more lightly. Beijing has simply upped the ante in response. The Philippines has also responded to  China’s claims by leaning on its military alliance with Washington, even going so far as to advocate interpreting the 1951 Mutual Defense Treaty in a way that includes the South China Sea—a position the United States has yet to endorse.

Nor do bold steps always produce a persuasive show of force. Manila’s deployment of a warship to intercept Chinese vessels poaching in the disputed Scarborough Shoal in April began a standoff that was only broken by a typhoon. Hanoi’s passage of a maritime law in June, requiring foreign naval ships entering the disputed areas to notify Vietnamese authorities, was countered by Beijing’s creation of a centrally administered outpost in the South China Sea, Sansha City, complete with its own military garrison.

In this game of tit-for-tat, Vietnam and the Philippines are clearly vulnerable. ASEAN has been too divided as of late to be of much help. The diverging interests of individual ASEAN states have stalled negotiations over a code of conduct agreement with China. The end result was a diplomatic deadlock at this month’s foreign ministers’ meeting in Phnom Penh, the first time in the organization’s 45-year history that ASEAN members failed to issue a joint statement.

With no mechanisms to manage tensions and the prospects of a resolution diminishing, directly pushing back against Beijing seems to be an ever escalating gamble for Hanoi and Manila. But domestic demand in Vietnam and the Philippines for hydrocarbon and fish stock is eroding the longstanding restraints on conflict. Furthermore, rising nationalism and a reluctance to appear weak before their respective domestic audiences are nudging them towards greater confrontation with China as the latter enlarges its maritime footprint. High stakes coupled with an increase of tensions means that a misstep by either China or Southeast Asian claimants can all too easily escalate the dispute to irreversible levels.

Stephanie Kleine-Ahlbrandt is the Beijing-based China and Northeast Asia project director for the International Crisis Group. The International Crisis Group recently released the second in a series of reports in the South China Sea. You can read the report here.