Could there be a sharp decline in the appeal of the dollar?

The US is taking advantage of the appeal of the dollar and its role as the dominant reserve currency to compensate, at a very low cost, for the shortfall in US domestic savings through a large and growing external debt. But could the appeal of the dollar decline sharply, which would create a serious problem in financing the United States? Such a decline in the appeal of the dollar could have several causes: The size of the US “twin deficits” (fiscal and external); A structural deterioration in the economic situation in the United States (decline in the participation rate, dominant positions, etc.); The decline in the international diplomatic and military role of the United States; The greater credibility of the euro (due to the development of more cooperative policies between euro-zone countries, the increasing retention of European savings in Europe).