With fuel prices spiking because of the Iran war, Trump is proposing to waive the federal gas tax — a levy that funds the Highway Trust Fund, which finances roads and bridges. The actual pump savings would be modest; the political return is not. This is a classic pressure-valve move: manufacture a visible, attributable number at the register while the underlying cause — a war this administration is managing — stays off the receipt. Highway infrastructure absorbs the real cost later, quietly.