Here's something that doesn't always make headlines: sometimes companies expand abroad for boring, practical reasons. Taiwan Semiconductor Manufacturing Co. (TSM) is building massive chip factories around the world, and while everyone wants to credit tariffs or geopolitical chess moves, the real driver is simpler—Taiwan is running out of room.

Taiwan Institute of Economic Research President Chang Chien-yi laid it out plainly. Companies in Taiwan face hard constraints on domestic expansion because the island lacks sufficient land for large-scale industrial projects. You can't exactly plop a multibillion-dollar semiconductor fab in downtown Taipei's Xinyi District and call it a day. This reality, Chang explained, is what's actually driving firms to pump up their foreign direct investment, the Taipei Times reported.

The Trade Deal That's Got Everyone Watching

Of course, the timing makes things interesting. Chang's comments came right after a tentative U.S.-Taiwan trade arrangement where Taiwan's semiconductor and tech firms, led by Taiwan Semiconductor, agreed to invest at least $250 billion in the United States. In exchange, Washington would slap a 15% tariff on Taiwanese goods—the same rate applied to South Korea, Japan, and the European Union.

That's sparked plenty of hand-wringing about whether Taiwan is hollowing out its industrial base. Chang pushed back on that narrative, estimating that 75% to 80% of Taiwan's semiconductor supply chain will stay put on the island through 2030, despite American ambitions to grab more production. He cited Taiwan Semiconductor Chairman C.C. Wei's position that overseas investments respond mainly to customer demand, not government arm-twisting.

The contract chipmaker is indeed ramping up its U.S. presence in Arizona, but economists say only a small slice of its most advanced chip production will actually migrate stateside anytime soon.

Arizona Gets Bigger, But Taiwan Keeps the Crown Jewels

Chung-Hua Institution for Economic Research President Lien Hsien-ming put some numbers on it: fewer than 15% of Taiwan Semiconductor's most advanced manufacturing processes are likely to relocate to the U.S. by the end of President Donald Trump's second term. Current construction schedules make Washington's stated goal of shifting 40% of Taiwan's chip supply chain to America before 2029 pretty unrealistic, he noted.

Lien pointed to the chipmaker's Arizona footprint, where the company is dropping $65 billion to build three fabs and has committed another $100 billion for additional fabs, assembly plants, and a research center. The company has started installing equipment at its second Arizona fab, which should hit mass production in 2027, and broke ground on a third fab this year. Those later projects won't reach full production before Trump's term wraps up.

Taiwan Semiconductor continues expanding in Arizona to serve customers like Nvidia Corp (NVDA), bolstered by that new U.S.-Taiwan trade deal with its lower 15% tariff rate. The company envisions a massive Arizona "gigafab" hub as the anchor of its U.S. strategy and has been buying up land to support future expansion.

So yes, the geopolitics matter and the trade deals create incentives. But sometimes the most important constraint is the most mundane one—you need somewhere to put the factory.

TSM Price Action: Taiwan Semiconductor shares were up 1.03% at $336.15 during premarket trading on Tuesday, according to market data.