SHENZHEN, China — In a grand hotel ballroom on Tuesday, Huawei executives laid out a soaring vision for the future. The Chinese electronics giant, already the world’s biggest supplier of the equipment that powers the wireless age, now wants to provide the digital backbone for artificial intelligence, the internet of things and other transformative technologies.

But that future is increasingly looking as if it will not include the United States.

Last week, the company laid off five American employees, including William B. Plummer, the executive who was the face of its Sisyphean efforts to win over Washington, according to people familiar with the matter. Huawei has also been dialing back its political outreach in the United States, these people said — which could end a decade of mostly fruitless efforts to dispel Washington’s accusations that the company has ties to the Chinese government.

Huawei’s tactics are changing as its business prospects in the United States have darkened considerably. On Tuesday, the Federal Communications Commission voted to proceed with a new rule that could effectively kill off what little business the company has in the United States. Although the proposed rule does not mention Huawei by name, it would block federally subsidized telecommunications carriers from using suppliers deemed to pose a risk to American national security.

Like other major tech companies, whether American or Chinese, Huawei (pronounced “HWA-way”) has been caught in the crossfire as the Trump administration ratchets up efforts to stop China’s high-tech ambitions. The two countries are waging a new kind of cold war, and with each increasingly suspicious of the other’s technology, winners are chosen based on national allegiances.