United States-Philippines relations seem to be heading for rocky times. Philippine President Rodrigo Duterte said on Sept 10: "I am not a fan of the Americans… in our relations to the world, the Philippines will pursue an independent foreign policy." His spokesman has reiterated the need to chart a new direction for an independent foreign policy.

What do these statements signify? What motivates them?

Apart from the President's personal animus against Americans and their misdeeds during their colonial rule in the Philippines in the first half of the 20th century, he wants multibillion-dollar investments in infrastructure from China to undergird the Philippine economy. He would like to strike a deal with China on the South China Sea dispute but without compromising his country's sovereignty and independence.

It will not be easy to do so because China continues to maintain an uncompromising stance on the South China Sea after the Permanent Court of Arbitration ruling which favoured the Philippines. It has continued to build military-related infrastructure on the artificial islands it has already created in the Spratly group and there is no assurance that it will not seek to enlarge and militarise Scarborough Shoal, closest to the Philippines.

China could seek a significant political price for a deal, possibly including some distancing of the Philippines from defence relations with the US. The Philippines military, which depends much on US military support, would be opposed to such a concession as would be significant parts of the Manila political establishment.

At present, there is no prospect of any termination or substantial reduction of American military forces' access to Philippine bases as agreed to under the 10-year long Enhanced Defence Cooperation Agreement signed in 2014. Mr Duterte himself has said that he would abide by the agreement. However, further strains in the bilateral relationship are likely as Mr Duterte's sensitivity to criticism meets the obduracy of the US Congress, which will not keep quiet on human rights abuses and may review aid to the Philippines.

The essential ingredients for the security of East and South-east Asia are balance of power, international rule of law and functioning cooperative security institutions like the Asean Regional Forum and the East Asia Summit. All three are important but without an underlying balance of power, the other two will not be effective in the present strategic environment.

As former Singapore Prime Minister Lee Kuan Yew used to say, only the US can balance the growing power of China in the region. However, given the present inward- turning mood of the American public because of slow economic growth, budgetary constraints, long weary wars in the Middle East and perceived ill effects of globalisation, there is increased recognition among regional states of the need to facilitate the American presence by making it easier for US political leaders to justify it to the American people.

Singapore, not a US ally, has since 1992 hosted the Logistic Group Western Pacific after the Americans vacated their bases in the Philippines. South Korea and Japan, US allies, are today doing far more. They not only provide bases for the US military but also pay large sums of money for the upkeep of the US forces in their countries. Meeting American expectations of "burden sharing" was the key factor behind Prime Minister Shinzo Abe's efforts to strengthen the ability of Japan's military to work with allies, in particular the US, in "collective self-defence". Even Japan's embrace of the Trans-Pacific Partnership has been significantly motivated by the need to keep the US engaged.

Access to Philippine bases is important for the US military as the bases in Japan and Guam are too far from South-east Asia. Other South-east Asian countries, afraid of offending China, are reluctant to provide the amount of access needed for a serious military contingency.

The felt need of many regional countries, in some cases not publicly expressed, for the US to provide the necessary balance is based on hard-headed calculation of national interests, not on any special pro-US sentiment which, where it exists, is purely incidental and hardly relevant. Nor, for the same reason, is it motivated by any dislike of China. Indeed China's rise and its civilisation is widely admired.

President Duterte, having spent many years as a mayor of a provincial capital far away from Manila, is a novice in foreign policy and strategic relations. But he is learning and will understand the need to make foreign policy decisions that best serve the interests of his country.

The military power of the Philippines is minuscule and its gross domestic product (GDP) of about US$300 billion (S$410 billion) is about the same as tiny Singapore's. Without the US strategic presence, nearby China, with its rapidly expanding military muscle and a GDP of US$10 trillion and growing, will clearly be the dominant power in the region. Will such a strategic environment give the Philippines more freedom and space for a more independent foreign policy? It is, as they say, a $64,000 question.

• The writer is senior research fellow and coordinator of the Regional Strategic and Political Studies programme at the Iseas - Yusof Ishak Institute.