WASHINGTON—The Trump administration scored a victory against the regime in Beijing this year through its “Clean Network” campaign that booted Huawei Technologies Co. out of critical telecommunications infrastructure in many countries. The effort, while not well-publicized, secured an array of commitments from governments to exclude untrusted vendors from their fifth-generation (5G) wireless networks. As of this month, more than 50 nations, representing over two-thirds of the world’s economy, and 180 telecom companies had joined the “Clean Network” initiative led by the U.S. government. The alliance includes 26 of the 27 EU member states, as well as technologically advanced countries such as Japan, Israel, Australia, Singapore, Taiwan, Canada, New Zealand, and India. This triumph for the U.S. government seemed unthinkable at the beginning of this year, as the Chinese telecom giant, a dominant player in the global 5G market, seemed unbeatable. For years, the United States had sought to convince its …