[Column] How will the US uphold deterrence when it runs out of weapons?

The US weapon stockpiles are running low, not just due to the ongoing war with Iran, but also due to a systemic crisis and strategic malaise. The US military has become a weakened giant unable to sustain prolonged conflicts. Former President Donald Trump criticized his predecessor Joe Biden for wasteful generosity in supporting Ukraine, which was based on the fact that the US lacks an endless supply of weapons.

Gen. Dan Caine and other military leaders had warned that an extended conflict could cause personnel losses and put pressure on key ammunition stores. With the Iran war, analysts estimate that the US has used one-third of its prewar stock of guided weapons, with some critical systems showing more than a 50% attrition rate. Restoring reserves to prewar levels could take three years for some weapons systems to the early 2030s for others.

The US' munitions stockpile was already insufficient for a major war with China before the Iran war. The just-in-time production system adopted by US defense industry in the post-Cold War years is unsustainable in a protracted, multifront conflict. This "generational annihilation" of conventional deterrence was first recognized and exploited by Iran, which has demanded that the US stop threatening Iran, lift sanctions, return frozen assets, pay war reparations, withdraw naval and air assets, and halt attacks on Iranian proxy forces.

Russia's war against Ukraine highlights the consequences of depleted American strength, as Ukrainian air defenses, vulnerable due to depleted Patriot interceptors, have been pounded by Russian missiles. Washington is likely to scale back its Indo-Pacific strategy to a more selective focus on limited interventions due to resource constraints.

The US military's inability to immediately deploy overwhelming conventional forces on all fronts in the event of simultaneous crises raises questions about the effectiveness of the ROK-US alliance and the US nuclear umbrella compensating for gaps in national security.