In his commentary ("The world under President Trump / Beginning of the end of US strategic leadership in Asia"; yesterday), Professor Hugh White suggested that United States President-elect Donald Trump's likely approach to China's challenge in Asia is to step back.

There are several factors the United States should consider before it decides on its course of action.

For example, would China take a more aggressive approach in its expansion of influence in the region, especially with regard to the South China Sea territorial disputes?

This is an unknown but very critical factor in the game plan.

Other factors include how Japan, India or Asean nations would react to the actions of the US and China in the region. These countries can play quite a significant role in tilting the balance.

If smaller nations feel threatened, or if the atmosphere in the region turns confrontational, new alliances among Asian nations themselves or with external powers could also develop.

When deciding which option to take, the US should not ignore the interests and concerns of nations in the region. Let us hope that it would think more deeply and not act hastily.

Singapore is more vulnerable than other nations when the region becomes unstable. Should the US opt to scale down its presence in the region, would we need to form new alliances or strengthen our existing ones with our strategic partners?

Singapore may need to re-examine the longstanding Five Power Defence Arrangements it has with Britain, Australia, New Zealand and Malaysia, if the US takes less interest in its alliance with Australia, New Zealand or Britain.

Albert Ng Ya Ken