India, May 29 -- A US trade court has ruled that Donald Trump's "liberation day" tariff scheme is illegal. To be sure, the judgment seems to rest on a constitutional technicality rather than the economic merits of tariffs. This is because the court has observed that Trump was wrong in invoking emergency powers in issuing the executive order which announced the tariffs.

Whether or not the tariffs have already become infructuous is something we await clarity on. However, it does seem that unless the court ruling is ignored in some way, the Trump administration will have to seek the US Congress's approval to reinstate the tariffs. In principle, the courts have done the right thing in reinstating the agency of the legislature vis-a-vis the e...