Anti-missile Systems — Tech Evolutions

Entry	Year	Description	Impact
N/A (Treaty Abrogation)	2002	The unilateral withdrawal of the United States from the Anti-Ballistic Missile (ABM) Treaty of 1972 is a critical event, though not an 'amendment' to a constitutional article. The ABM Treaty limited the deployment of missile defense systems by the US and Soviet Union. Its abrogation by the US in 2002, citing new threats, fundamentally altered the international legal landscape for missile defense development.	Removed a major international legal constraint on the development and deployment of national missile defense systems, leading to accelerated programs in the US and subsequent proliferation of advanced BMD systems globally. It shifted the strategic deterrence paradigm and sparked concerns about a new arms race.
N/A (Policy Shift)	Ongoing	While not a formal amendment, the continuous evolution of national defense policies and strategic doctrines to incorporate advanced anti-missile systems reflects a significant policy shift. Nations are increasingly moving towards 'integrated air and missile defense' (IAMD) concepts, which combine air defense against aircraft and cruise missiles with ballistic missile defense.	Leads to greater investment in sophisticated multi-layered defense systems, integration of diverse sensors and effectors, and enhanced interoperability among allied forces. This policy shift is driven by the proliferation of diverse and advanced missile threats, requiring a more comprehensive defensive posture.