The reality is that, well before Trump became president, global trade imbalances were shrinking. Figures from the International Monetary Fund (IMF) show that, as a share of the economy (gross domestic product), the U.S. current account deficit hit a recent peak of 5.8 percent in 2006 and dropped to 2.4 percent by 2017 . The comparable figures for China were 9.9 percent of GDP in 2007 and 1.4 percent in 2017.
That is from Bob Samuelson. Arguably China is already running a trade deficit, especially if you account for the fact that some of their major exports, such as iPhons, are built using an international supply chain, and most of the actual value-added does not come from China (though it solely counts as a Chinese export in the numbers).