Congress dismisses NIE, declares Iran a nuclear threat

Iran poses a nuclear weapons threat to the United States and its allies, according to the National Defense Authorization Act for Fiscal Year 2008 H R 4986 passed 369-46 by the US House of Representative yesterday, even though the National Intelligence Estimate concluded that that Tehran abandoned its atomic weaponry ambitions in 2003.

Section 229 of the Act states that:

Congress finds that Iran maintains a nuclear program in continued defiance of the international community while developing ballistic missiles of increasing sophistication and range that:
(1) pose a threat to--
(A) the forward-deployed forces of the United States;
(B) North Atlantic Treaty Organization (NATO) allies in Europe; and
(C) other allies and friendly foreign countries in the region; and
(2) eventually could pose a threat to the United States homeland.

HR 4986 mandates that it is the policy of the US to "develop, test, and deploy, as soon as technologically feasible, in conjunction with allies and friendly foreign countries whenever possible, an effective defense against the threat from Iran."

Essentially, this calls for the establishment of the controversial missile defense shield, which is threatening to reignite the cold war and start a new arms race with Russia.

The findings of the Congress contradict the NIE released last month which concluded with “high confidence” that “in fall 2003, Tehran halted its nuclear weapons program” and that "Tehran had not restarted its nuclear weapons program as of mid-2007". Link

Why?