Trump is just USA, its jut one country, plus his hands are full of lies at the moment.
Trump is leader of the largest economy on earth, with a military budget / capability larger than the next 8 nations combined.
Its only just the largest economy. As to military, who of the other top 8 would they attack?
No - it's still by far the largest economy - GDP US$ trillions
Not according to this https://www.investopedia.com/articles/investing/022415/worlds-top-10-economies.asp
We often hear that China will take over in a few years. China is developing, the US is old and has poor and neglected infrastructure. Think of it has a grand house that hasn't been maintained. Also, the US population of 300 million is developed, China has yet to develope its 1.3 Billion.
EU GDP is 17.1 a major. The world needs to get over the US superpower. They can waste public funds to be the military superpower if that makes them feel good
PPP GDP isn't a particularly useful measure in a global trade comparison - you're trading guns and ammo, Harley Davidsons and bourbon in real currencies, not currency adjusted based on the relative cost of hamburgers or noodles or a pair of shoes in each country.
Trump and Russia are trying to destroy the EU - and so far things are going quite well for them.