If you look at the “2012 Worldwide Threat Assessment” presented on February 16 by Director of National Intelligence James R. Clapper to the Senate Armed Services Committee, and compare it with the “2011 Worldwide Threat Assessment,” you find a startling development. Last year, the assessment was “we do not know whether [North Korea] has produced nuclear weapons, but we assess it has the capability to do so.” This year it is, “North Korea has produced nuclear weapons.”

The new assessment is apparently based on a revised judgment, not new intelligence, since it cites the same evidence as the 2011 assessment, but comes to a different conclusion. It illustrates the fact that the key is nuclear weapons capability, not production. Once capability is achieved, the critical technical line has been crossed; after that, production is a political decision that cannot easily be discovered until after the fact. As Iran heads down the same path traversed by North Korea, consider Clapper’s February 16 responses to Sen. Lindsey Graham on Iran’s activities:

SEN. GRAHAM: Do you think they’re building these power plants for peaceful nuclear power generation purposes?

CLAPPER: That remains to be seen.

SEN. GRAHAM: You have doubt about the Iranians’ intention when it comes to making a nuclear weapon?

CLAPPER: Uh-h, I do.  I, I, uh, I —

SEN. GRAHAM: You’re not so sure they’re trying to make a bomb? You doubt whether or not they are trying to create a nuclear bomb?

CLAPPER: I think they are keeping themselves in a position to make that decision, but there are certain things they have not yet done and have not done for some time.

SEN. GRAHAM: How would we know when they have made that decision?

CLAPPER: I am happy to discuss that with you in closed session.

SEN. GRAHAM: Well I guess my point is that I take a different view. I’m very convinced that they’re going down the road of developing a nuclear weapon. I can’t read anyone’s mind, but it seems logical to me that they believe that if they get a nuclear weapon they’ll become North Korea …

What we do know Iran has done – and has been doing for some time – is build a “covert” uranium enrichment facility, constructed underground in the mountains near Qom, hidden for years from the international community, with enrichment operations commencing in “blatant disregard” of multiple UN and IAEA resolutions, with “no plausible justification” except to bring Iran “a significant step closer to having the capability to produce weapons-grade highly enriched uranium.” The quoted language is from Hillary Clinton’s press release last month. The huge underground site is a major expansion of Iran’s program.

Last month, President Obama said America is determined to prevent Iran from “getting a nuclear weapon.” Secretary Panetta said if we “get intelligence that they are proceeding with developing a nuclear weapon then we will take whatever steps necessary to stop it.” But waiting for intelligence about getting a nuclear weapon – instead of preventing nuclear weapons capability – sets the red line where a violation can neither be timely detected nor effectively reversed, as the North Korea experience demonstrates.

A group of 32 senators introduced a resolution on February 16 that would affirm a “vital national interest” in preventing Iran from “acquiring a nuclear weapons capability,” and reject any policy relying on “containment” of a nuclear weapons capable Iran. It is an effort to avoid repeating the sad story of American diplomacy and intelligence between 2003 – when President Bush declared the U.S. would “not tolerate nuclear weapons in North Korea” – and 2012, when Director Clapper acknowledged that North Korea has produced nuclear weapons.