During his first term as president, when Donald J. Trump started a tariff war to pit the United States against China, Malaysia bet on both sides. The Southeast Asian nation aggressively courted American and Chinese companies with tax breaks and other goodies.

The strategy worked. Malaysia, a linchpin in China’s push for influence through its economic might, has brought in multibillion-dollar investments from companies including Texas Instruments and Lam Research of the United States and Alibaba and Geely of China.

With Mr. Trump headed back to the White House, and threatening to disrupt global trade again, Malaysia is hoping it can build on that approach with a plan to turn its southern tip into a hub for multinational companies looking for a safe haven.

It involves an economic agreement with its neighbor Singapore, historically sometimes more of a competitor than a partner. Singaporean officials are embracing cooperation, too. Negotiators are wrapping up the details of a special Malaysian economic zone where companies will be given financial incentives to build factories.

The point is to give multinational companies based in Singapore, an island city-state on Malaysia’s southern border, the room and workers they need to expand their operations. Construction and investment on new facilities started this year and the prime ministers of Malaysia and Singapore will sign a final pact when they meet at an annual retreat on Dec. 8 and 9.

The timing is opportune: American companies have put in place plans to cut their China ties in the days since Mr. Trump was re-elected, while Chinese companies have been reaching out to Malaysian officials.