This piece was originally published in Lawfare in April 2018
The United States is party to a number of international intelligence sharing arrangements—one of the most prominent being the so-called “Five Eyes” alliance. Born from spying arrangements forged during World War II, the Five Eyes alliance facilitates the sharing of signals intelligence among the U.S., the U.K., Australia, Canada and New Zealand. The Five Eyes countries agree to exchange by default all signals intelligence they gather…