When I spend $100 at the grocery, my capital account (money) goes down by $100, but my goods account (groceries) increases by $100. My grocer's goods account decreases by $100, while his capital account increases by $100. There's a trade balance, whether my grocer is down the street, in another state or in another country.
Say Japan's Sony Corp. sells me a $1,000 television. My capital account goes down by $1,000, but my goods account rises by $1,000. Suppose Sony doesn't buy any wheat, corn, cotton or cars from Americans. People are tempted to say that there's a trade deficit. Not true. Instead of using that $1,000 to buy goods from us, Sony might purchase stocks and U.S. Treasury bonds from us -- in other words, invest in America. When Sony sells me a television, the corporation's goods account (called "current account" in international trade) goes down by $1,000, but its capital account (stocks and bonds) rises by $1,000. Lo and behold, again a balance of trade.
By the way, it would be great if foreigners didn't buy anything from us and just gave us cars, computers, televisions, clothing and other goods in exchange for slips of paper with pictures of past presidents such as George Washington, Andrew Jackson and Ulysses Grant. We could live the life of Riley. The world would bestow all manner of goods and services upon us, and all we'd have to do is have a few Americans employed printing dollars that foreigners would hold precious and keep.