Is it better to be a borrower (like the United States) or a lender (like the euro zone)?

The United States has a structural external deficit, so it is a structural borrower from the rest of the world. Since the crisis, the euro zone has built up a structural external surplus, so it is structurally a lender. Is it better to be a borrowing country (like the United States) or a lending country (like the euro zone)? The borrowing country is able to have a higher investment rate and therefore higher long-term growth than the lending country. This is confirmed by a comparison between the United States and the euro zone; But the risk for the borrowing country is the potential for a crisis caused by excessive external debt: a balance-of-payments or a currency crisis. But given the status of the dollar and the euro as reserve currencies, is this really a risk for the United States and the euro zone? If this risk does not exist, then the United States has the better strategy. Indeed, the United States has not had a balance-of-payments crisis in 40 years despite its chronic external deficit.