The current quarrel over the imposition of supplemental tariffs on the goods of two of our trading partners has now moved from the floor of the executive to the chamber of the court, where it belongs. The question being argued, in essentials, is not whether the tariffs are wise — that is a question for the legislature and the executive together — but whether the statutes the executive has invoked actually authorize them.

I will not prejudge the outcome. I would observe only that the discipline a free nation owes itself, when it acts under the cover of a treaty or a statute touching foreign commerce, is to act within the words of the instrument it claims to act under. A power asserted on doubtful authority is a power weakly held. A power asserted on plain authority — even if the policy is contested, even if the merits are divided — carries the force of law in a way the doubtful assertion cannot.

If the existing statutes do not authorize the tariffs the executive has imposed, the proper course is to ask the Congress to authorize them, not to read the existing texts beyond their fair sense. The shortcut is tempting; the precedent is corrosive. A nation that grows comfortable with executive assertions of trade authority beyond the statute will find, in some future season, that the same assertion is used for ends it did not intend.