Trump is emphatically
not correct.
See for example Wiki's fine article, and many many others available on the net, on "Balance of Trade."
A few excerpts:
from Adam Smith's Wealth of Nations:
In the foregoing part of this chapter I have endeavoured to show, even upon the principles of the commercial system, how unnecessary it is to lay extraordinary restraints upon the importation of goods from those countries with which the balance of trade is supposed to be disadvantageous.
Nothing, however, can be more absurd than this whole doctrine of the balance of trade, upon which, not only these restraints, but almost all the other regulations of commerce are founded.
from Wiki:
The notion that bilateral trade deficits are bad in and of themselves is overwhelmingly rejected by trade experts and economists.
from
Foreign Policy,
3 (2017):
Gramer, Robbie. "Economists Take Aim at Trump Trade Theory -- Again."
"Navarro’s comments drew skepticism from trade experts and economists across the political spectrum, who said that line of thinking on economics was flawed. Economists say trade deficits aren’t an indication of good or bad economic times, but rather a function of savings and investments. (The United States enjoyed a stellar trade surplus during the Great Depression in the 1930s, for example.) “He won’t find economists — either on the left or the right — that believe trade deficits are this huge a problem,” Chip Roh, a former assistant U.S. trade representative and trade lawyer, told Foreign Policy. “It doesn’t make economic sense.” “When economists hear, ‘Our goal is reduce the trade deficit,’ it baffles us,” Gordon Hanson, a trade economist at the University of California, San Diego, told FP. “He’s either using it as a cheap political ploy or there’s a misconception — he doesn’t understand how it operates.”
