I’ll try to explain it clearly, he takes a lot of short term and impulsive decision leading to small visible gains in the near future but with bad impact on the long term. And his decision usually please his businessmen’s friends. Like increasing oil production, lower taxes, which boost artificially stock market and lower oil prices, lowering short term inflation. But on the other hand it means less income for the government, higher debt, higher long term inflation. That’s why you saw recently a boom in stock market, decrease in oil prices and increase of 10y bond reflecting long term inflation.
It’s a typical decision of businessman, more focused on short term gains rather than long term. In all trading companies/big corporate it’s the same reasoning, mainly because end of year bonuses are calculated based on current year EBIT. No one cares about the long term in global business, even if they pretend they do.
And those short term decisions have impact over the world, leading mainly to trade war, it could be on oil versus Russia and Saudi Arabia who have lower marginal cost than the US so they can put US out of the market by increasing production and leading to huge losses for US shale oil companies on mid-long term. And it decreases the dominant position of the US globally and especially on long term geopolitics.
It leads to a lot of volatility in the global market which is usually what traders want to make money. And China benefits a lot from this because they are really focused on long term global dominance