Are savings better used in the United States than in the rest of the world?

The United States has a chronic external deficit (which is going to increase thanks to the policies being implemented by the Trump administration) and a growing external debt: it therefore has to attract savings from the rest of the world. This transfer of savings from the rest of the world to the United States is shocking: per capita GDP and per capita capital are much higher in the United States than in the rest of the world, which normally implies that the marginal productivity of capital is lower in the United States than in the rest of the world, and therefore that capital should flow from the United States to the rest of the world. T his argument could be countered with the assertion that even though per capita capital is higher in the United States than in the rest of the world, the marginal return on capital remains higher in the United States because of increasing returns to scale and because the business environment (legal, financial, research, etc.) is better. But this argument does not convinc e , as the capital that heads to the United States primarily finances the US fiscal deficit and not US companies. As the US fiscal deficit certainly does not entail a high degree of efficiency, it is therefore true that global savings would be better used in the rest of the world than in the United States.