In the first decade of the second millennium, the USA plans to build a $50 billion national missile protective shield around the USA and those European allies who agree to take part. This is considered necessary because of the potential threat from "rogue states" like Iraq and North Korea who may, in future, menace the USA with missiles. Critics of the plan argue it could affect the [Treaty Between the United States of America and the Union of Soviet Socialist Republics on the Limitation of Anti-Ballistic Missile Systems], in force since 1972, and could trigger a new arms race with Russia and China. Europeans emphasize the need for dialogue with potential adversaries.