U.S. Representative Thaddeus McCotter, a Michigan Republican, has called on CFIUS to reject the deal. Huawei's take in 3Com, which markets intrusion detection systems, would "gravely compromise" U.S. national security, he said in a House floor speech in October.
It is common knowledge that the Chinese army has launched internet attacks against US government agencies. And there is information that Huawei, which is run by an ex-army senior officer, provides info on technology partners to the Chinese army helping facilitate their spying forays.
While US companies help the CIA and NSA spy on other countries, there is no reason the US should approve a deal that helps the Chinese army spy on the US.