India, May 21 -- The dastardly terror attack in Pahalgam last month triggered an Indian response in the form of Operation Sindoor. An intense engagement, in which the Indian armed forces scored hits in the most secure coordinates of Pakistan's airspace, followed. Three days later, on the request of the DGMO of the Pakistan army, an understanding was reached between both countries to stop operations. One way of making sense of this sequence is to use the Game Theory framework. A concept called deterrence can be particularly illuminating. Deterrence is a strategy where one player (e.g., a country) prevents another's undesirable action (e.g., a terrorist attack) by threatening a costly response. The fundamental property of deterrence is that it always lies in the future. One can only deter future acts of terrorism by the threat of a future punishment. In order to be effective, such threats should involve substantial costs. This is obvious. What is usually non-obvious is that threats should be credible, in the sense that it should be rational for the player making them to carry out if the situation demands. Otherwise, the threat is just a bluff that will be ignored by the adversary. So, the real question in the present context is whether Operation Sindoor and the following public declarations have enhanced the expected magnitude and credibility of Indian threat posture contingent on any future act of terrorism. The answer seems positive. Let us examine. First, the direct cost of this conflict for Pakistan - the cost of closure of airspace, neutralisation of at least one air defence system, cost of intercepted UCAVs, cost of missiles fired for intercepting Indian drones, operational cost of maintaining the army at high alert levels for many days - must be substantial. Even conservative lower bound estimates suggest that the IMF loan installment of $1 billion - secured after hectic negotiations - was burned in just three days of conflict. And remember that known costs are just the tip of the iceberg. At least eight Pakistan Air Force bases and four radar sites were hit, and such sites store extremely expensive military hardware. Such costs would be prohibitive even in normal times. They are particularly onerous now, as Pakistan is under IMF obligation to compress its government expenditure in order to generate a fiscal surplus. The money to replenish destroyed assets and used inventory will be hard to come by. Second, looking at the Indian action following Uri, Pulwama, and Pahalgam, a gradually increasing intensity of punishment is clearly discernible. To borrow the terminology of economics, the marginal cost of terrorism is going up. Extrapolating the trend, one can predict that any Indian response to future acts of terrorism will be much more severe. This was clearly signalled by Vice Admiral AN Pramod, Deputy Chief of Naval Operations, by underlining the "overwhelming edge" of the Indian Navy. In this context, it may be noted that naval actions have enormous economic impact, as they affect the port cities of adversaries. So the threat of Indian action following future acts of terrorism seems substantial. But what about credibility? What is the way to make one's threats more credible in general? One way of making threats credible is to have self-imposed costs for backing down in future. This can be done for example by a public declaration of intent. If you do not carry out the threat, you lose face. Notice how both the Prime Minister and armed forces have publicly declared their intent of retaliation for future acts of terrorism. Moreover, democracies have an in-built mechanism of making credible threats, namely the public demand for retaliation. The public demand for punishment following any terrorist action makes it politically very costly for the incumbent to back down. Additionally, by striking firmly three times in a row after acts of terrorism, India has earned the reputation for retaliation. In the event of non-retaliation, this hard-won reputation will be lost. This will increase the cost of backing down substantially. Another way of making threats credible is to reduce the cost of carrying out the threat. This can, for example, be done by investing in defensive capabilities. It should be noted that unlike Pakistan, India has the fiscal space for enhancing the credibility of threat posture through budget allocations and defence procurements. The above analysis suggests that Operation Sindoor has a reasonable chance for establishing deterrence against acts of terrorism, with the caveat that transition to a new normal is never perfect and takes some time. The current understanding between both countries does not look like a stalemate. To be sure, this is not a checkmate either. But most professional games of chess do not end with checkmate. They end when one player realises that the checkmate has become inevitable. In an ideal world, neighbours can live next to each other with mutual understanding and respect. When that is not possible, peace based on deterrence is the only alternative. Deterrence, when successfully established, avoids conflict and war. This is an imperfect, but effective, way to peace and prosperity....