R. SuryamurthyNew Delhi, March 12 -- Washington has opened a sweeping trade investigation into the industrial policies of 16 economies-including India, placing several of New Delhi's most ambitious manufacturing sectors under scrutiny. The probe, launched under Section 301 of the Trade Act of 1974, will examine whether government support for industries such as steel, solar modules, petrochemicals, electronics and automobiles is creating global "excess capacity" that harms American manufacturers.

Officials in Washington say the exercise is meant to protect the domestic industry from distortions in global markets. Critics argue it may instead be laying the legal groundwork for another round of tariffs.

Among the sharpest critics is trade ec...