The Asian Financial Crisis of 1997

Through the mid-1990s, Thailand, Indonesia, South Korea, and their neighbors were held up as economic success stories, growing fast on the back of exports and heavy foreign investment. Much of that investment came in a specific, fragile form: local banks and companies borrowed heavily in U.S. dollars, because dollar interest rates were lower than local rates, while their revenues and assets were mostly in local currency. Most of these currencies were also loosely pegged to the dollar, which made the arrangement feel safe — as long as the peg held, the currency mismatch didn't matter.

The trouble started in Thailand in mid-1997. The baht came under selling pressure as investors began to doubt Thailand could keep defending its peg given a widening current account deficit, and the central bank spent its reserves defending it until it simply ran out and was forced to let the baht float — a currency crisis nearly identical in shape to the UK's ERM exit five years earlier, but with a far more damaging twist. As the baht fell, Thai borrowers with dollar debts suddenly owed dramatically more in local currency terms to service the same debt, since their income was in baht but their obligations were in dollars.

This is the currency mismatch problem that made the crisis so severe and so contagious. Once investors saw it play out in Thailand, they began pulling money out of other countries with similar dollar-debt-plus-currency-peg setups, on the reasonable suspicion the same dynamic would repeat. It did — Indonesia, South Korea, and Malaysia all saw their currencies collapse in turn within months, a cascade now studied as the textbook example of financial contagion between countries with no direct economic link beyond a shared vulnerability.

South Korea's case was especially dramatic given its size and sophistication — the won lost roughly half its value, several major conglomerates collapsed under dollar debt they could no longer service, and the country accepted a large IMF program with strict conditionality attached, a bailout many Koreans experienced as a genuine national humiliation.

The crisis is the direct historical reason "original sin" — a country's inability to borrow abroad in its own currency — is treated as a first-order risk factor in emerging-market analysis today, since it's precisely what turned a currency devaluation into a full-blown solvency crisis for borrowers across the region.