Iran-Israel lesson: Effective missile defence is costly and could be risky too

Drones are relatively easy to shoot down, given their slower speeds, but countering a swarm of them is still no mean feat. Intercepting cruise, ballistic and hypersonic missiles, on the other hand, is harder, given their respectively increasing speeds, but American-made systems have proven capable of doing so at high levels of effectiveness. This defensive capability will get even better in the future.

Missile defence has already changed the way battles are fought over land and sea. It will also influence geopolitics and strategy.

For the foreseeable future, the marginal cost of missile defence will be higher than that for offence. A single interceptor missile used by Israel or Ukraine costs between $100,000 and $500,000, compared to the $20,000 per drone that Iran and Russia spent. If more than one missile is required to take down an incoming drone, the average cost of successful interception goes up even higher. In the Red Sea, the US navy used a $2 million missile to intercept a $2,000 drone that Yemen’s Houthi insurgents launched at one of its ships. The cost of defence, thus, is five to 1,000 times the cost of offence. This means that despite its accuracy, it only makes sense to deploy missile defence to protect high-value targets.

As Wes Rumbaugh, an analyst at the Centre for Strategic and International Studies argues, using a $2 million missile to protect a $2 billion warship is worth it, regardless of how cheap the Houthi drone is. It does, however, call into question the usefulness of big expensive warships, unless they are used to protect even higher value targets. Yes, it is a case of turtles all the way down.

With attackers having a massive fiscal advantage, they can prevail in a conflict by bleeding the defender. At an average cost of $250,000 per interception, Israel and its Western allies spent a minimum of $80 million in a few hours. Only rich and large countries can sustain this. Thus, Ukraine and Israel depend on the US for weaponry as well as for the aid money that pays for it.

Kyiv is in a tight spot today because it is running short of interceptors and the money it depends on Washington for. Similarly, for all its advanced capabilities, Israel’s capacity to defend itself depends on continued weapons supplies and financial support of the US. In the events of 13 April, it appears that American forces took down over 60% of the drones and missiles that Iranian forces launched towards Israel.

Ergo, any country deploying missile defence has a critical dependence on the country supplying it. At crunch times, the supplier must be both willing and able to deliver large numbers of interceptors at short notice.

Some of India’s missile defence systems are of Russian and Israeli origin, which gives them both leverage over New Delhi’s foreign policy. The impact on strategic autonomy can be mitigated by indigenous systems. But even if such systems were available, they would still be costly and run against considerable budget constraints.

My colleague Prakash Menon, who retired as lieutenant general from the Indian Army, explained to me that if interceptor stocks fall below a certain threshold, the usual military response is to counter-attack and destroy the facilities used to launch the drones and missiles. That is what Israel did on Friday. Such an escalation, however, comes with its own risks, further escalation and damage prominent among them.

That’s not all. While a 99% success rate in interception appears extraordinarily good, it is no cause for comfort in a nuclearized context. If one nuclear-tipped missile gets through out of a hundred, it is still one too many. One reason Russia and China are building hypersonic missiles is to be able to have a greater chance of penetrating the US anti-ballistic missile shield. A missile defence with a 100% success rate is very ephemeral. A small improvement in the attacker’s delivery capability will restore nuclear vulnerability, and worse, the path towards a nuclear exchange.

It would be a folly to believe that superior military force or amazing technology alone provides peace and security. Rather, they provide time and space for politics, diplomacy and statesmanship to negotiate a solution. Walls, border fences, missile defence shields, surveillance technologies or strategic superiority can lull a society and its leaders into believing that the underlying problem has gone away. It surprises them when they discover that it had not. The reluctance to find political compromises is the biggest risk of impermeable missile defence.

Tailpiece: Iran’s massive aerial attack did not cause any physical damage in Israel. But it did shatter deterrence.