Japan built the modern semiconductor industry. By the mid-1980s it held more than half of global DRAM market share and was the presumptive long-term dominant force in chip manufacturing. Within two decades that position had been absorbed almost entirely by Taiwan and South Korea. The transfer of leadership was not the result of a single competitive reversal. It was structural, compounding, and in several respects self-inflicted.

The 1986 Trade Agreement

The proximate wound arrived through policy. The US-Japan Semiconductor Trade Agreement of 1986 set floor prices on Japanese chip exports and required that foreign companies reach a 20% share of the Japanese domestic market. Washington framed it as reciprocity. The practical effect was to hand American and Korean competitors a margin-protected breathing window at exactly the moment when fab investment requirements were beginning to escalate sharply. TSMC was founded the following year. The timing was not a coincidence — the agreement had altered the risk calculus for a pure-play foundry model that Japan had dismissed and the US had reason to encourage.