"Keep telling us why the sale of two high-tech firms to China (with significant national security implications) is a good idea ..."

Never told anybody that.  Read my comments (again,) Chuck.  Where did I say I thought it was a good idea, and why?  Maybe I do...maybe I don't.  Frankly, I don't think it's any of my business--or yours.  It's owners-and-shareholders business.  I've said THAT many times.  So, on that basis, the PM and govt. step aside.

Now, about security risks.

Chuck, you gotta ask yourself, if the issue is really "security" how cum the Pentagon and White House haven't really pressured the fed. govt. to STOP THIS SALE COLD??  They haven't.  And even when asked, ambassy folks clam up! Now, it could be US senators/congressmen are all stunned and dazed by Trump craziness, but, surely SOMEBODY down there would be doing more than advising the Pentagon to "review" Norsat contracts. If the mighty a- red-under-every-bed US ain't worried...why are we?