Red lines aim at the illustration of borders for your opponent’s activities. These borders may be geographical boundaries that your opponent is forbidden from penetrating, the acquisition of too-dangerous weapons, or political lines in the sand such as the annexation of occupied areas. Thus, a red line is an ultimatum and a particular sort of commitment to a certain response, defined by its nature, its intensity, and its timetable. Placing red lines is an integral part of national deterrence.

Israel must deter the Iranian government from developing nuclear weapons, instead of bringing it to ask itself whether to continue its project or to be deterred. Actually, now all ambiguities and unknowns have become clear, and Iran may seek a variety of options to bypass or cross the red line.

But red lines will also enslave Israel, because they allow Iran to test Israel’s credibility and readiness to realize its deterrent image, despite the dynamic changes in current situations that may change red lines, rendering them irrelevant in circumstances that aren’t yet known.

Conditions may change, new alliances may be forged, new counter-surface-to-surface missiles (SSM) systems will be developed and deployed, or there will be upheaval in Iran, and so on. But Israel, once it has committed itself, must react in accordance with its declared red lines, otherwise its deterrent image will be diminished

Red lines and inflexible deterrence, which were effective until the end of the Cold War about 20 years ago, are losing their efficacy in the rapidly changing environment and with different national systems of values. Consequently, a revolution in pragmatic deterrence is required. Red lines policies should be replaced with a strategy of “gray zones” that uses ambiguous terms, and allows flexibility in choosing its types of responses, reaction times, and measurements of power and intensity. Iran — the deterred nation — would be unsure of when and how, and of the volume of the Israeli or American response.

For instance, why should it be sure that Israel will respond with a conventional and predictable reaction?

There is deterrence against enemies and there is a sort of deterrence vis-a-vis friendly nations like the US: Does the president of the United States understand that desperate and isolated Israel may react with desperate means?

Perhaps Israel should raise gray clouds of concerns that in the face of existential threats it will see no alternative but to use “existential means” to survive. Such an ambiguous statement may achieve stronger deterrent effect than any red line. The illustration of well-defined gray areas will preserve deterrent effectiveness and enhance the flexibility of the threats of possible response.