Currency wars

In 1944, forty-four nations gathered at Bretton Woods, New Hampshire, to design the post-war monetary order. The system they built — dollar-gold convertibility, fixed exchange rates, the IMF as lender of last resort — was explicitly designed to prevent the competitive devaluations that had deepened the Great Depression. For twenty-seven years, it worked. Then Nixon closed the gold window, and currency warfare became the permanent background condition of global finance.

Most people think of war as tanks, aircraft carriers, and casualty counts. That’s the 20th-century version. The 21st-century version looks like freezing $300 billion in Russian central bank reserves overnight, cutting Iranian banks off from SWIFT, or China quietly accumulating enough U.S. Treasury bonds to make any sudden sell-off a financial weapon of mass destruction. The battlefield has moved from Normandy to the foreign exchange market, from the trenches to the trade balance.

The eight weapons of economic warfare

Every economic weapon that nations deploy falls into one of eight categories. Once you learn them, you can decode virtually any geopolitical confrontation in the financial press.

1. Competitive devaluation. The oldest trick in the book. Weaken your currency so your exports become cheaper and your trade partners’ factories lose orders. China managed the yuan below market value for decades, accumulating $3 trillion in foreign reserves while building the world’s largest manufacturing base. Japan has intervened to weaken the yen more than a dozen times since 2000. In the 1930s, every major economy tried this simultaneously — a beggar-thy-neighbor spiral that made the Depression worse for everyone.

2. Sanctions and asset freezes. The nuclear option of financial warfare. When Russia invaded Ukraine in February 2022, Western nations froze roughly $300 billion in Russian central bank reserves held abroad — the largest asset seizure in history. They disconnected major Russian banks from SWIFT, the messaging system that facilitates virtually all international bank transfers. Iran has lived under escalating sanctions since 1979. North Korea is almost entirely cut off from the global financial system. The weapon works because the dollar-denominated system is a network, and being expelled from the network is economically devastating.

3. Dollar weaponization. Because roughly 88% of all foreign exchange transactions involve the dollar, and because virtually every international bank needs a U.S. correspondent banking relationship, the United States has unique leverage. Secondary sanctions — threatening to cut off any bank that does business with a sanctioned entity — effectively force the entire global banking system to enforce American foreign policy. BNP Paribas paid $8.9 billion in fines in 2014 for processing transactions with Sudan, Iran, and Cuba. The message to every other bank was clear.

4. Debt-trap diplomacy. Lend money to nations that cannot sustainably repay, then extract strategic concessions when they default. China’s Belt and Road Initiative has extended roughly $1 trillion in infrastructure loans to developing nations. Sri Lanka, unable to service its debt to China, handed over a 99-year lease on its strategic Hambantota Port. The IMF’s structural adjustment programs of the 1980s and 1990s did something similar — conditioning bailout loans on privatization, deregulation, and market opening that often served Western corporate interests more than local populations.

5. Trade manipulation. Dumping goods below cost to destroy foreign competitors, then raising prices once the competition is dead. Subsidizing domestic industries so heavily that foreign competitors cannot match the price. The U.S.-China trade war that began in 2018 involved tariffs on $550 billion in Chinese goods and $185 billion in U.S. goods — a tit-for-tat escalation where each round damaged consumers and businesses on both sides while the underlying structural issues remained unresolved.

6. Capital controls and speculative attacks. In 1992, George Soros bet $10 billion that the British pound couldn’t maintain its peg to the European Exchange Rate Mechanism. He was right. The Bank of England spent $3.3 billion in reserves defending the peg, failed, and Soros made $1 billion in a single day. In 1997, speculative attacks on the Thai baht triggered a cascade that destroyed currencies across Southeast Asia, wiped out decades of savings for millions of families, and reshaped the political landscape of the region. Capital controls — restrictions on money flowing in or out of a country — are the defensive weapon against these attacks, but they come with their own costs: reduced foreign investment and the signal that your economy may be fragile.

7. Energy weaponization. In 1973, OPEC embargoed oil exports to the United States and Netherlands for supporting Israel in the Yom Kippur War. Oil prices quadrupled. The U.S. economy entered a recession that lasted years. Russia used the same playbook with European natural gas — cutting flows through Nord Stream to pressure Europe over Ukraine. The U.S. Strategic Petroleum Reserve, holding roughly 400 million barrels, exists specifically as a counter-weapon.

8. Technology denial. The most recent and potentially most consequential weapon. The U.S. CHIPS Act and Entity List restrictions aim to prevent China from accessing advanced semiconductor technology — specifically, the extreme ultraviolet lithography machines made by ASML and the advanced chips designed by NVIDIA. The logic: if you can’t make the chips, you can’t build the AI, and if you can’t build the AI, you lose the next decade’s military and economic competition.

Why economic warfare is replacing kinetic warfare

There is a reason nations increasingly reach for economic weapons before military ones. Economic warfare is faster to deploy (sanctions can be implemented in hours; mobilizing an army takes months). It causes fewer visible casualties (though the human toll of sanctions-induced poverty is real and large). It is harder to attribute and easier to deny (“We’re just adjusting our trade policy”). It is cheaper for the attacker. And it faces fewer legal and political constraints — there is no Geneva Convention for currency manipulation.

But economic warfare has its own escalation dynamics that most people don’t understand. Sanctions create incentives for the sanctioned to build alternative systems (Russia’s SPFS, China’s CIPS, the BRICS push for non-dollar settlement). Dollar weaponization accelerates de-dollarization — every time the U.S. freezes assets or threatens secondary sanctions, it gives every other nation a reason to reduce dollar dependence. Trade wars raise costs for domestic consumers while rarely achieving their stated goals. The weapons are powerful but not free, and the blowback is often measured in decades.

The de-dollarization question

The most consequential currency war unfolding right now is the slow-motion attempt by China, Russia, and the BRICS nations to reduce dependence on the U.S. dollar. China’s digital yuan (e-CNY) is being tested for cross-border settlement. The mBridge project connects the central banks of China, Thailand, the UAE, and Saudi Arabia for direct settlement without touching the dollar system. Russia and China have shifted roughly 90% of their bilateral trade to rubles and yuan.

Is this the end of dollar dominance? Almost certainly not in the near term. The dollar’s share of global reserves has declined from about 72% in 2000 to about 58% today — a meaningful shift, but not a collapse. The dollar’s deepest advantage isn’t military backing or reserve status but the depth and liquidity of U.S. capital markets. There is simply no other market where a sovereign wealth fund can park $500 billion with confidence it can get it back tomorrow. That structural advantage will erode slowly, not suddenly.

But the direction matters more than the speed. A world where the dollar accounts for 45% of reserves instead of 58% is a world where U.S. sanctions are less effective, U.S. borrowing costs are higher, and U.S. foreign policy has fewer tools short of military force. That world is coming — the question is whether it arrives in ten years or forty.