President Trump’s threat to use steep tariffs to break up what critics say is a virtual monopoly on the production of advanced microchips could become a reality in a matter of days, but Taiwan has dispatched a high-powered economic delegation to Washington this week in a bid to persuade the administration to change course.

Mr. Trump recently said he could put tariffs of up to 100% on semiconductor chips — the kinds that power smartphones and are indispensable for market-leading companies such as Apple and Nvidia — made by Taiwan Semiconductor Manufacturing Co. Critics say the Taiwan-based company has an essential monopoly on the global microchip market. About 90% of global leading-edge semiconductor chip production is concentrated in the island democracy.

Specialists see a significant security problem for the U.S. for multiple reasons, including TSMC’s operation of some facilities in mainland China. In the event of a Chinese military strike on Taiwan, they say, the global supply chain for high-end, cutting-edge chips would be severely disrupted and would put America’s technological and military power at significant risk.