Redlines

Tertrais: "The expression “red line” has become a regular feature of the global policy debate. It has notably been used with regard to the Iranian nuclear programme, the Syrian civil war, and the Ukraine crisis.

Although its increasingly frequent use is a recent trend, the term refers to a well-known political phenomenon: preventing an event or occurrence that is deemed unacceptable. The expression always involves interaction between at least two agents on the international stage, and suggests the idea of a game-changing fact or act, yet it can have several distinct meanings. It is used, for instance, in diplomacy to define one’s own internal position (“our red line should be…”) in preparation for a negotiation, or to state that such and such a concession would be unacceptable. For example, in 2014 Iran affirmed that maintaining its uranium enrichment capability is a “red line” that it would not allow to be crossed in the framework of any agreement with the international community . The Palestinian Liberation Organization (PLO), for its part, holds the view that “the Green Line [the 1949 armistice line, author’s note] is a red line” in the context of the negotiations to create a Palestinian State . Likewise, the expression is used by governments to privately define a threshold for action (for instance, a casus belli, or the precise terms of commitment to an ally). In the midst of the current chaos in the Middle East, it has been suggested that the destabilisation of Jordan would be intolerable and thus constitute a red linefor Israel .

Moreover, it is in Israel – a country that has for decades maintained a constant policy of deterrence towards its State and non-state adversaries – that the term has doubtless been most frequently employed since the 1970s . The country’s red lines are often unstated publicly and are only communicated to its adversaries through the use of coercive means, aiming to develop a learning process in the adversary’s mind regarding deterrence (for example, in the context of the ongoing Syrian crisis, Israeli strikes to signal the prohibition of strategic arms transfers by Iran or Syria to Hezbollah). Israeli red lines are also sometimes conveyed directly to the adversary in a private and discrete fashion, if necessary through the use of an intermediary .

Other countries have adopted such an approach in the Middle East. In the 1980s, the leaders of Hezbollah were deterred from targeting the Soviet presence in Lebanon by a demonstration carried out by Moscow: the Soviet intelligence services targeted an important religious dignitary and mutilated him following an attack on the country’s diplomatic representatives . In the 1990s, the U.S. intelligence services carried out what was later described as “an intelligence operation” in order to deter Iran from again targeting U.S. interests following the Khobar Towers attack (American lodgings in Saudi territory) in 1996; the nature of this operation has not been made public – it appears to have threatened Tehran with revealing the identity of all the Iranian agents in the region known to U.S. services – but the warning was received loud and clear .
Analysing why and how red lines can prove effective or not is thus in large part a subset of studying deterrence: avoiding an adverse action through the threat of retaliation (deterrence by “threat of punishment”), or indeed, much less commonplace, through action aiming to prevent the adversary from attaining its goals (deterrence by denial”) . The corresponding notion of ultimatums is an entirely different matter: they involve coercion, not deterrence, as the goal is to force an actor to do something, rather than to prevent it from doing something.

Given their importance in the international landscape, it is useful to try to understand when and how it can be appropriate – if at all, for red-lining is often highly criticised – to draw a red line when trying to deter an adversary."