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As far as I understand, Huawei is currently accused of supplying hardware to Western countries that could be used for spying by the Chinese government.
But why would this be a big deal? Properly designed communication channels are supposed to be secure from MITM attacks and thus it shouldn't matter if the Chinese government has a back door. And if your communications are prone to MITM attacks, then you have a bigger problem on your hands than foreign meddling.