One might argue that the best way to protect workers and the domestic economy is to stop trade with other nations. Then the whole circular flow of inputs and outputs would stay within our borders. But if we decided to do that, how would we get resources like cobalt and coffee beans? The United States simply can’t produce some things, and it can’t manufacture some products, such as steel and most clothing, at the low costs we’re used to. The fact is that nations—like people—are good at producing different things: you may be better at balancing a ledger than repairing a car. In that case you benefit by “exporting” your bookkeeping services and “importing” the car repairs you need from a good mechanic. Economists refer to specialization like this as advantage.
This means that no country can efficiently produce everything it needs, so it makes sense to trade with others. Countries focus on producing goods and services they are best at making and trade for the things they cannot produce easily or cheaply. This specialization helps the economy grow because it lowers costs, increases efficiency, and allows everyone to benefit from trade.