On a Tuesday morning in April, a container ship loaded with automotive parts sat anchored outside the Port of Los Angeles, its cargo on hold while the importer's legal team tried to calculate the exact duty it would owe. That scene — repeated at dozens of ports across North America and Asia — captures the practical cost of what analysts are calling a "rolling legal justification" strategy, in which the Trump administration continues to search for new statutory grounds to support its sweeping tariff programme rather than settling on a single, stable framework. The administration has already invoked at least three separate legal authorities: the International Emergency Economic Powers Act, Section 232 of the Trade Expansion Act of 1962, and Section 301 of the Trade Act of 1974. Each statute carries different procedural requirements, different caps on presidential discretion, and different exposure to court challenges.

When one legal pillar is weakened by litigation — as has already occurred in several federal cases — the White House has signalled its readiness to pivot to another, effectively resetting the clock on any legal certainty businesses might have anticipated. For multinational firms, the consequence is a planning horizon measured in weeks rather than years. Capital expenditure decisions in manufacturing, which typically require 18-to-24-month lead times, are being deferred at scale. The Asian Development Bank has already revised its regional growth forecasts downward, citing trade policy volatility as the primary variable, while European export associations from Germany to Portugal have flagged the same concern in formal submissions to Brussels.

The deeper problem, economists argue, is that tariff levels matter less than tariff predictability. A company can price a known 25 percent duty into its supply chain; it cannot price in a legal theory that may change before the goods clear customs.