This is why security is not a "one size fits all" exercise. The first thing you must do is define your threat model.

The reason the Chinese government doesn't want to build their telecom system on Cisco hardware is the same exact reason the USG doesn't want to do the same with Huawei hardware. Because neither government is delusional enough to think that parts/service/updates wouldn't be immediately sanctioned in times of war.

The US and China are already sanctioning each other's tech. The risk of building critical infrastructure on it is obvious.

> The US and China are already sanctioning each other's tech.

It's not symmetrical. Since Trump, the US has been extraordinarily aggressive in its use of sanctions against Chinese companies, whereas China has been very reluctant to retaliate directly.

The US has sanctioned hundreds of Chinese tech companies. China has only recently begun to retaliate in kind, but has so far only sanctioned a few US companies (Micron is the only prominent example that comes to mind).

It isn't. And I didn't say it was. But the current state isn't the ultimate risk that is being considered. The ultimate risk is war, under which both the US and China would invoke defense powers to compel industry to act in their respective nations' interest, and would apply wide sanctions.

The zero-sum thinking of the Trump and Biden administrations, in which China is seen purely as a threat and all sorts of cooperation and economic integration are being rolled back, makes war more likely. The US is not compelled to ban Huawei and sanction all sorts of Chinese tech firms - that's a choice.