Mmmm, I don't think that there are too many economists here being a technology site, this is how it looks to me, however, Trump has now initiated a trade war, and in a trade war there are no winners. There is only increasing cost.
America needs resources from other nations, it simply can not produce enough, at the desired levels of quality at desired prices to sustain growth. By slapping a tariff on goods coming from china all the US has done is made all those products more expensive for consumers. Since the costs of the increase will be passed to consumers. This will in turn lead to a reduction in demand and a reduction in demand will result in people being fired.
Reciporically, China has imposed dollar for dollar tariffs on American imports, specifically targeting sectors of the US economy that are based in regions of America that supported Trump. China is taking a targeted pain approach to its response. Much like the US it too needs to import more than it can produce (in certain trade sectors) with a population nearing 1.3 Billion people Soy is but one example.
As the tariffs bite China which has been buying land in other nations for cultivation, will seek alternate trading arrangements, indeed it has initiated the belt and road project to construct an alternative global trade network at a cost of around $1 Trillion. The more Tariffs the US inflicts, the more likely the alternatives are to be used by former allies.At a time when the US has retreated from the world stage through its failure to fill its diplomatic ranks (there are still over 1,000 empty diplomatic positions) all the US has done is create a vacuum where the loudest voice being heard is China's.
And thats not to say that China has not been a bad actor. from patents to sceince China has copied and stolen blueprints, designs and processes that were developed in the West. It then reaps the benefits of this without needing to pay for the development costs. However there are mechanism's by which these kinds of infringements can address this kind of illegality. A trade war won't either address or stop it.
Conversely America is not some kindly benevolent caretaker showering gifts on the rest of the world especially since it owes the rest of the world $21 Trillion in the form of its national debt. Rather the US has tried to assert its supremacy in all matters not least of which militarily. However that power is built on alliances with other nations, some of which are bought, others are made in exchange of services, goods technologies and so on, while more via influence. While the US rides around the world in the most expensive war machine constructed, it still needs its international allies to provide ports of call for re-supply and rest. Having military power is one thing, being able to project it is quite another. Without alliances to the EU the US would not have been able to use certain airbases that put its fighters in range of targets in the middle east. Whether America likes it or not it needs to maintain its relationships. Without them you lose supply lines and when you lose supply lines you lose wars of which the US is currently engaged in 8 (including proxy wars).
America remains a threat to its enemies because of its proximity to them via its alliances and those alliances have now been strained. This doesn't just threaten America's capabilities militarily, it threatens them economically too. The more unstable world trade becomes; the more damaged the US dollar becomes. Economics and trade are built on stability and while the US Dollar remains a reserve currency for now, other countries are beginning to look at the process of shedding that reliance and transfer their holdings to another currency.
To sum up, the US' influence is a complex weave of threads that are being damaged by the man at the top. there is little intelligence to the actions being taken, they are just simply being taken because they can be enacted swiftly and that makes Trump look busy which is good for the cameras.
The economic pain will come in three forms to average American life firstly in the form of job cuts as trade tariffs bite businesses will move production and jobs to where it is cheapest to conduct business. Secondly when the tax cuts offered by Trump's tax plan expire for middle and low income brackets (only the rich will retain theirs). And thirdly; having passed legislation to gut Social security and medicaid programs to pay for those permanent tax cuts to the wealthy leaving middle and low income America with nothing but a prayer when the full fallout from the trade war arrives.