And, recent history tells us, the US does spy on its allies, its allies' governments and business.
I've always taken the US alarmist position on chinese equipment to at least partially means that they fear not being able to bug the rest of the world as easily once everyone network are not filled with US gears.
IIRC, the US doesn't actually produce any 5G cellular equipment. The alternatives to Chinese equipment are European: Ericsson and Nokia.
EDIT: It appears Intel is working on 5G.
Perhaps not ban, but I would say testing can only tell you so much. It applies to pretty much to any digital system short of exhausting every possible state. Most modern devices can easily have more states than what is possible to test. Moreover most also run software so it's the same as claiming testing is a 100% sure fire way to create bug free software.
Let alone a innocuous back-door. While testing increases the bar for anything malicious to slip by it does not eliminate it entirely. Really it comes down to trust. This applies to all hardware though and I would say everyone is unsophisticated enough to just rely on tests.
Like VHDL was created so the Department of Defense could have something to check ASIC behavior against. I am not saying testing is useless. For instance a malicious actor better be certain that their backdoor can't be found, but they can't be a 100% certain that testing won't find it. It cuts both ways. Testing may not find things, but any adversary may not be sure that their back-door may not be found via testing.
The Five Eyes, often abbreviated as FVEY, is an anglophone intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom and the United States. These countries are parties to the multilateral UKUSA Agreement, a treaty for joint cooperation in signals intelligence.
The more pertinent question is who the Canadians trust more, China or the US, given the possibility of undetectable backdoors in equipment sold by both. I'd bet on an ally against an adversary.
The non-political person in the room, Christopher Parsons, said the Americans expressed “some skepticism”.
Sanger is a national security correspondent for the NYT and recently wrote a book about cyberwar and cyber-sabotage called "The Perfect Weapon."
One key thing I got out of it is that, even though the U.S. has forbid the use of any Huawei products in the U.S. 5G network build-out, he thinks it would be very difficult for even the U.S. to sufficiently test Huawei's 5G infrastructure products — he points hardest at their software-based switches — to ensure that they are not fundamentally compromised in ways that could give great advantage to the Chinese government.
Audio and transcripts available at the above link.
However, this generally applies to all software and hardware. I guess the big question is there a possibility of innocuous back-doors vs your run of the mill exploitable bug.
I will add if Canada has a testing/analysis regime that can conclude such a strong assertion they have made quite a big break through overall when it comes to verification.
I'm also not confident in our government's ability to prevent full-on Chinese state actors from tampering with such an assessment.
Added: though this should not be taken as a reason to defer to the U.S. government either. Our institutions regularly fail to serve their purposes, and the first step to solving that is to actually care that it's the case.
While I don't agree with this approach I can see why it happens. For example I have a smattering of news articles to prove incompetency.
and a bunch of professionals in what amount to a twitter war.
If the Canadian government doesn't want people talking negatively about them then there needs to be more transparency. Not to the level of risking a breach, but something along the lines of a list of safeguards they are implementing. I wouldn't ever consider one safeguard a solution. If somebody feels the need to call out where the information is, I would legitimately like to read it.
Drawing from my roots the Canada Wheat board was always surrounded by heated arguments and controversal decisions. There was the UN wheat scandal but that is more a matter of if you believe they are evil and not their level of incompetancy.
They received a significant amount of name calling due to their decisions and policies, but I can't recall any significant missteps in their application of the policies they set out to act upon.
Like the possible states that hardware and software have can be enormous that only the simplest of devices can be exhaustively tested.