zyo: Apple, Samsung have all been prosecuted and fined with IP infringements before. How's that any different? Should they be banned around the world too?
That is exactly the difference. Samsung and Apple have been prosecuted and sorted out by the courts. Huawei ignores the local laws and refuses to front up in court. So a resolution in this case can not be found in a court room the problem escalates from the Justice system to the government who pull out a bigger, much worse hammer to squash the problem with.
Then why is the President of the USA citing a 'security concern' as the reason for blacklisting them?
If the US is going to start using this as a negotiating tactic for trade disputes, then it's going to become clear that major global tech firms are at risk of severe disruption if they do business from there.