An American ‘Iron Dome’ Would Help the U.S. — and Our Allies

A ddressing his supporters at a rally on the eve of his inauguration, Donald Trump promised that his administration would construct a “great iron dome missile defense shield, which will all be made in the U.S.A.” The following evening at the commander in chief’s inaugural ball, the newly sworn-in president again raised his desire for “a nice iron dome.” Indeed, defending the American homeland against long-range missile attacks was a recurrent theme for candidate Trump on the campaign trail, where he pledged “to build the greatest dome of them all.” And, as President Trump’s executive order signed just this past Monday evening suggests, constructing an “iron dome” will be high on the Pentagon’s list of priorities.

The Trump administration would be wise to trust its instincts on protecting the homeland against long-range attacks. But in doing so, Trump should not lose sight of the critical role missile defense can play in enabling the projection of power on a global scale to secure America’s farther-flung interests. Missile defense should complement global engagement, not replace it. To lose sight of this role risks opening fissures between Washington and its allies.

Trump’s remarks on this critical issue have often been long on hyperbole and short on providing a rationale for improved homeland missile defense. In an August interview with Elon Musk, Trump noted that the United States now faces multiple nuclear-armed adversaries — but “it just takes one maniac to, you know, start something.” He expressed grave concern that the Biden administration had left the country on the precipice of thermonuclear war and without adequate defenses.

Only after the election, though, did it become clear that Trump’s rhetoric was more than mere campaign bombast designed to differentiate himself from his political rivals. Trump’s key aides, like his national security adviser, Mike Waltz, began to make the rounds on the Sunday morning talk shows, ensuring that Trump’s enthusiasm for missile defense remained in the public spotlight. But here, too, little explanation was offered for why the country required a revamped homeland missile defense architecture. In Waltz’s case, the rationale was reduced to an “all-of-the-above protection of U.S. airspace” from direct attacks conducted by shorter-range drones, longer-range ballistic missiles, and maneuvering hypersonic glide vehicles.

Left unsaid by Trump and Waltz was the all-important role homeland missile defense plays in enabling the U.S. military to project power on a global scale. After all, if America lies entirely vulnerable to small-scale coercive attack, would Washington still respond in the extreme case of Beijing threatening a nuclear strike against the continental U.S. at the outset of an amphibious invasion of Taiwan? If so exposed, would an American president hesitate to surge conventional power from the homeland into the western Pacific? And would America’s allies take note of its vulnerability at home, question Washington’s credibility as a security partner, and decide to remain on the sidelines? These are all dilemmas an improved missile defense architecture designed to defeat limited Chinese and Russian nuclear attacks can help resolve.

To be sure, the president’s team likely appreciates the role of missile defense in projecting power on a global scale. But it’s vital that in moving the “iron dome” forward, the administration clearly expresses to its allies the connection between continental defense and America’s ability to maintain alliance commitments.

On this point, Trump officials should look no further than the rollout of America’s last major campaign for a homeland missile defense architecture. In a 1983 nationally televised address, President Ronald Reagan called on America’s scientific community “to give us the means of rendering nuclear weapons impotent and obsolete . . . to begin to achieve our ultimate goal of eliminating the threat posed by [Soviet] strategic nuclear missiles.” Such a defensive shield, the president concluded, “could pave the way for arms control measures to eliminate [nuclear] weapons themselves.”

Reagan correctly understood the value of homeland missile defense in projecting power to thwart Soviet aggression and defend allies. But he neglected to consult NATO partners prior to the televised address, which provoked suspicions in Western Europe that America’s nuclear security guarantee was less than ironclad. Reagan’s messaging also made European partners fear that homeland missile defense would turn the United States into an invulnerable island unto itself — so much so that Washington might fold up its nuclear umbrella that had extended over Western Europe.

Trump’s team can avoid all this by never losing sight of homeland missile defense’s critical role in enabling the defense of international and domestic regions.

Missile defense can — indeed, it must — play a vital role in shoring up America’s global interests and alliances. But rhetoric matters — especially presidential rhetoric. A carefully crafted campaign is required, constructed in close coordination with allies that stresses the interdependence between continental defense and power projection.