If Israel takes military action against Iran, it will be one of the biggest decisions in the history of the state. The risks involved will make it unprecedented.

There is no comparison between such a decision and the ones that established and implemented the so-called Begin doctrine: the decision by Menachem Begin's government to attack the Osirak reactor in Iraq in 1981 and the attack on the nuclear facility in Syria in 2007. In terms of both the complexity of the military operation and the uncertainty about the consequences and where they may lead, there is a qualitative difference between the legacy of the past and the challenge of the present.

The seriousness of the challenge requires as open and thorough a public discussion as possible. But unfortunately, such a discussion has been virtually nonexistent, even on a basic conceptual level. Instead of a public discussion there has been a belligerent press, which makes demagogic use of statements that intensify the message of the politics of fear. These include expressions such as "Iran is galloping toward a bomb" and a "second Holocaust" that Israel must prevent. Such discourse creates a feeling that if Iran is not attacked, and soon, we have no choice but to accept a nuclear Iran.

It's doubtful whether the people making those statements are capable of giving them a precise (technical and political) interpretation. It's doubtful whether they have a suitable answer to the question: When should Iran be considered a nuclear state? Where exactly is the red line? What is the precise significance of such a line and what makes it red?

One thing is clear: As long as Iran is a member of the Nuclear Non-Proliferation Treaty, it will not be able to test a nuclear device or declare that it has one. Also, as long as Iran is subject to the treaty, it will not be a nuclear state according to the accepted definition of such a state.

It's true that under cover of the treaty Iran can get very close to the nuclear threshold and still claim - as it claims now - that it is not deviating from its legal obligations under the treaty. Iran as a threshold state can perhaps even position itself a few weeks away from a nuclear test. Such an Iran, despite supervision by the International Atomic Energy Agency, will of necessity be opaque; there will always remain a fear that it is working in secret, including making weapons in secret. But even in such a case, Iran would be considered a threshold state, not an actual nuclear state.

Even those who disparage the practical limitations of the Nuclear Non-Proliferation Treaty (as Israelis tend to do) must recognize that it is almost impossible for Iran to be a nuclear state in the full sense without withdrawing from the treaty. And even if it is outside the treaty, it will take Iran years, many years, to make the transition from a threshold state to a mature nuclear state. Such a transition is not trivial; certainly it is not inevitable, even if we look at the experience of states that in the past were considered threshold states and were not bound by the treaty's restrictions.

For example, India, which carried out a nuclear test in 1998, is still making this transition slowly, and many experts say it should still not be considered a mature nuclear state. Even Pakistan, whose nuclear path was faster and more purposeful than India's, needed about a generation to become a nuclear state to all extents and purposes. In its nuclear behavior Iran is more like India than Pakistan.

It's ironic that an Iran under attack would probably become more determined and purposeful in its nuclear ambitions. After an attack, Iran would abandon the treaty in protest, declare its right to nuclear arms and almost certainly succeed in implementing it.

The public discussion in Israel about a nuclear Iran is simplistic, inadequate, confused and confusing. It reflects to some degree our own biases. We come from a culture of national security in which nuclear opacity has been exploited to the hilt to create a specific model of deterrence. The result is that when we look at Iran we see ourselves: how we would behave in a similar situation. But Iran is not Israel exactly, and the Israeli experience does not necessarily reflect Iran's behavior. On the contrary, it leads to systematic errors when making assessments.

The writer is the author of the book "Israel and the Bomb." His forthcoming book, "The Worst-Kept Secret," will be published in the United States in September.