The Federal Reserve's opposition to digital money. The Federal Reserve and Treasury oppose issuing digital dollars to ordinary citizens. That’s a burden on our economy and threat to national security. Money is whatever people will universally accept. It must be portable and reasonably scarce — something not easily created but still capable of increasing in supply with the growth of commerce.

The Eastern woodlands Indians used shell wampum — the difficult to fashion clam and whelk shells were only found along Long Island Sound and Narragansett Bay.

In 17th-century London, goldsmiths invented modern banking by holding gold and sovereign coins for safekeeping and lending out their value in transferrable paper notes. For each ounce of gold or sovereign, money could exist in two places — receipts held by depositors and transferrable notes issued to borrowers.

Those morphed into modern banks — institutions with little interest in manufacturing objects from precious metal but taking deposits and earning interest on loans. Bank drafts and modern checking accounts followed.

Governments printed paper money that was accepted because they could tax their citizens’ ability to make goods and services. Cash was king, because greenbacks don’t bounce but checks do when issuers lack adequate funds at the bank.

National central banks took responsibility for regulating banks to protect depositors and ensure the supply of credit by requiring banks to keep a portion of their deposits on reserve in their vaults or at central banks.

Bank-sponsored credit cards came into use by charging transactions fees — about 1.5 to 3 percent. Those assure payment — checks can bounce but credit card payments to businesses are guaranteed by a pool taken from the 1.5 to 3 percent. The system has become increasingly digital — central and commercial banks keep electronic ledgers, and we pay bills on computers and through apps on smartphones.

Importantly, unlike transactions among ordinary businesses and consumers, bank-to-bank transactions — scored on electronic ledgers at the Fed — are terribly low cost, fast and secure.

Banks love it, because the Fed pays them interest on their reserves, and ordinary folks must pay the banks fees for the privilege of accessing the system. And it often takes days instead of minutes for private transactions to clear.

Vaguely citing legal, monetary policy, payment policy, financial stability, supervision and operational issues, the Fed refuses to let ordinary businesses and citizens have direct access to digital money by establishing accounts at the Fed’s regional banks. Even though those could provide virtually costless, terribly fast and absolutely secure private transactions — and make the economy run much more efficiently.

The Fed’s excuses are a smoke screen. Central banks in Sweden, Canada, Switzerland and the Caribbean have experimented with or are studying digital currencies, and China is planning on issuing digital yuan quite soon.

Digital dollars already in use among banks are increasingly the lingua franca of global commerce.

The United States accounts for only 8.8 percent of global exports but 40 percent of global trade and 88 percent of all foreign exchange transactions are denominated in dollars—for example, Mexican pesos into Japanese yen usually are done peso to dollar and then dollar to yen.

Through their global payments systems, Citibank and other banks worldwide that take dollar deposits provide the plumbing, and those make the dollar an offensive weapon in U.S. foreign policy. By denying access to U.S. banks and payment systems, Washington is smothering Iran’s economy.

In the eyes of our allies, the Trump administration overuses economic sanctions — for example, applying those to Iran when the United States withdrew from the nuclear treaty and on the construction of the Nord Stream 2 natural gas pipeline from Russia to Germany.

The Fed reacted with great alarm when Facebook announced plans last year to introduce a block chain driven digital currency backed by a basket of currencies such as the dollar, yen, pound and yuan. U.S. regulators pressured MasterCard, Visa and eBay to suspend participation.

China — unlike any other nation — can create a digital yuan that offers the speed, low cost and security of digital dollars. With its large reserve of dollars and trade surplus with the United States, Beijing could ensure its value stays constant against the dollar.

Our allies and adversaries have been looking for ways around the dollar payments system and digital yuan could be just that and supplant the supremacy of the dollar.

Then Chairman Powell and Secretary Mnuchin, Beijing not Washington could be applying the sanctions and calling the tune.

• Peter Morici is an economist and business professor at the University of Maryland, and a national columnist.