Last week, President Donald Trump boasted of the inclusion of the “Golden Dome” missile defense program in the One Big Beautiful Bill Act, which the House narrowly passed Thursday. The funding, initially set at a staggering $175 billion, is for a long-standing Republican fantasy: total U.S. impunity to attacks from other nations.

Experts are scratching their heads at President Trump’s ambitious, three-year timeline for Golden Dome, a next-generation missile defense system he says is essential for the future of U.S.