When businesses in two countries — say, India and Argentina — want to conduct a deal, they almost always arrange payment not in rupees or pesos but in dollars. Everyone wants to hold the world’s most trusted and liquid currency. Nearly 90 percent of bank-financed international transactions are conducted in dollars, a share that is close to all-time highs.

The world is on a dollar standard, and in some ways the reach of the dollar is expanding. When individuals and companies borrow from lenders in another country, they increasingly borrow in dollars, which now account for 75 percent of these global flows, up from 60 percent just before the global financial crisis in 2008. Even though the crisis began that year in the United States, American banks dominate global finance more now than they did before the crisis — in part because debt troubles have dogged banks in Europe, Japan and China even more persistently.

The share of countries that use the dollar as their main “anchor” — the currency against which they measure and stabilize the value of their own currency — has risen to 60 percent today from about 30 percent in 1950 and 50 percent in 1980. And those countries collectively account for some 70 percent of the global gross domestic product. In other words, most of the world chooses to live in a dollar bloc.

Critically, there is no sign that the dollar’s status on any of these measures — as a reserve, an anchor or the favored currency for cross-border transactions and loans — has declined since Mr. Trump took office.

In a dollar world, most countries are happiest when the dominant currency is cheap and plentiful. A strong dollar raises the cost of borrowing, which slows global economic growth and has often triggered debt crises in the emerging world. A weak dollar has the opposite effect, which is why the weakening of the dollar this year offers more evidence of its dominance: Partly as a result, the world is enjoying an unusually broad recovery encompassing every major economy.

The global embrace of the dollar matters not only as a sign of trust. Having the world’s favorite reserve currency is a practical advantage, lowering borrowing costs and boosting G.D.P. growth in America, while symbolizing great power status. Not surprisingly, then, China in particular has been eager to challenge the dollar’s supremacy.

Instead, the renminbi has gained no ground as a reserve currency and probably won’t as long as China’s financial markets remain largely closed, underdeveloped and subject to government meddling. One reason foreigners like to hold the dollar is that they know they will never get stuck with it, thanks to the vast, open and highly liquid American stock and bond markets.