How did the cutting edge, selfie-taking phone you bought get into a worldwide tech war?

After almost clinching a trade peace deal with China recently, US President Donald Trump had the Huawei chief financial officer arrested in Canada so she could be extradited to the US to face charges for allegedly violating its sanctions against trading with Iran, disallowed US companies from using Huawei and tried to convince countries around the world to stop buying Huawei.