Hypocrisy, paranoia, cluelessness, and yet...
Hmm, OK, It's OK for the US to supply IT kit to China. Like say Cisco, selling all them the it they use to run the Great Firewall, a clear cut case of the US aiding oppression, or all those copies of MS Windows and so on and so so forth, but it's not OK for the Chinese to take a commercial interest in one US networking company ?
I detect the sweetly sick scent of US trade hypocrisy here.
Paranoia, well, the US isn't actually at war with China, nor is it likely to be. They have to much in common, both are oppressive regimes who like to torture people and spy on their own citizens, both have pseudo capitalist economic frameworks that favour a small ruling elite while forcing the masses into effective slavery, etc, etc. If it wasn't for the Yank's irrational fear of the god damned Godless Commies, they'd be best buds, for sure.
Lets break the cluelessness down then, Firstly, if you're relying on a single vendor IDS solution (or just IDS appliances of any sort) for the security of your infrastructure, if you think that security comes in a magic box that you can just plug in and forget about, then you're already fucked. If your network is set up such that compromising such boxes is enough to FUBAR all your security measures, ditto. If you have failed to understand the concept of defence in depth to such an extent then the Chinese are the least of your worries, your "national security infrastructure" is already home to vast numbers of sKript Kiddies and bot-herders. Oh wait...
In addition to that, for a systematic compromise of kit at the silicone or software level, the controlling interest would have to have not just financial but operational control of 3Com such that they could corrupt the entire manufacturing process. Perhaps I'm naively optimistic, but I rather suspect that 3Com's employees would notice a bunch of ChiComs running about their production environment and fiddling with things. Add to that what ought to be a fairly rigorous QA process (just for the fact that they manufacture security critical kit, never mind the government contracts) and it seems a bit unlikely that such a large scale compromise could be accomplished without anyone noticing.
Still, I can see how selling a US company to a venture firm run by a former Red Army officer would make the average dumb yank apoplectic with rage, since they still seem to think of "communism" as some kind of awful communicable disease.
Anyway, the whole idea is dodgy isn't it, I mean it's not like there are any former US forces types working for VCs is it ? What ? There are ? Lots of them ? Oh well, that's that argument down the pisser then eh ?
In all fairness though, if I were the US military industrial complex, I'm fairly sure I'd react the same way, since 'difficult' is not the same as 'impossible', and the easiest (and cheapest) way to mitigate the risk is simply not to let the deal go ahead, so fair play to them really.