Exon-Florio

The "Exon-Florio" provision (section 721 of the Defense Production Act)
provides the President with authority to investigate proposed or pending
mergers, acquisitions, and takeovers by or with foreign persons to
determine their effects on national security. The provision also grants
the President authority to suspend or block those transactions that lead to
control of a domestic firm by a foreign person if the President determines
that the foreign purchaser might take actions that would threaten the
national security.