Re: "It is perfectly possible for the West [..] to decide on a coherent policy"
I think you overestimate Trump. In terms of what actually happened, Obama wasn't really a lot better and Bush was pretty dire. The difference is that Obama was too intelligent, and Bush too under the thumb of his nannies, to spill the beans.
The problem for the US, bluntly, is that a series of unfortunate trends have started to converge. One is that the long period of the dollar being the world's reserve currency backed by oil, which you need to fight wars and build the MIC, is slowly coming to an end.
Another is that as the US has exported a lot of manufacturing - not all, but quite a lot - it has become more dependent on litigating IP. Which is all very well, but it doesn't educate enough of its citizens to the IP-generating level, and the Koreans, Japanese, Central Europeans and the inhabitants of certain Chinese urban areas are very happy to fill the gap.
And the third is that US control of oil is threatened by a number of factors - Iran and certain South American states; the gradual shift towards gas, of which Russia has vast reserves, and the rise of renewables, threatening in the long run to obsolete both oil and gas.
The US is thrashing about, trying to maintain control by economic and shooting warfare, destabilisation of independent minded governments, and trying to force other countries not to use products made with foreign IP. They destroyed BlackBerry and Nokia in the phone industry, now they are trying for Huawei but they have run into a country a lot bigger than either Canada or Finland.
Nothing reasonable will come out of the White House till the US has its Suez moment. How that will happen, I dread to think.