What lessons from the politics of SDI might be helpful for Golden Dome? Don’t exaggerate. Reagan’s vision was seen by many as other-worldly, sapping SDI’s credibility.

Golden Dome proponents might avoid some of the disputes of the SDI era. Golden Dome recalls Reagan’s concept for SDI to defend the U.S. against long-range ballistic missiles.

The Golden Dome presents Canada with an opportunity to, in the words of one expert, “prove” itself to the United States after months of tensions because of Trump’s rhetoric and economic ...