The "Golden Dome": Midcourse Ballistic Missile Defense Technology and Broader Implications

The January 2025 “Golden Dome” executive order mandates development of, among other things, systems to defend the United States homeland against ballistic missiles from peer, near-peer adversaries, as well as those with smaller and less sophisticated arsenals. This is an important departure from long-standing policy which focuses US strategic missile defense efforts on countering a small number of long-range missiles from an emerging missile state, given that defending against the larger and more sophisticated nuclear arsenals of peer and near-peer states would be technologically challenging, extremely expensive, and strategically destabilizing.

The sole existing US system intended to defend against nuclear-armed intercontinental ballistic missiles (ICBMs) is the Ground-based Midcourse Defense (GMD) system, designed to counter a small number of North Korean ICBMs. However, after decades of effort and tens of billions of dollars spent, this system has yet to demonstrate reliable defense against a realistic threat. The March 2025 American Physical Society Panel on Public Affairs report concluded that “within the 15-year time horizon it considered, the GMD system cannot be expected to provide a robust or reliable defense against more than the simplest attacks by a small number of relatively unsophisticated missiles.”

This talk will review the technology of midcourse defense systems, including longstanding and contemporary challenges and technological trends, provide an analysis of the GMD system, and discuss why a Golden Dome program to reorient midcourse systems to defend against Russian and Chinese nuclear arsenals would be costly but ineffective, and would incentivize a destabilizing offensive-defensive arms race.