# Sentinel

The Sentinel Sinkhole: How a $141bn ICBM Upgrade Is Exposing Fault Lines in US Nuclear Renewal

The US LGM‑35A Sentinel ICBM programme has ballooned to roughly $141 billion and triggered a Nunn‑McCurdy breach after costs surged and schedules slipped. Much of the overrun stems from unexpectedly heavy investment in new hardened silos and associated infrastructure, creating risks to the timing and credibility of the US land‑based deterrent.