India’s successful test of the Agni-4 ballistic missile from Odisha’s Chandipur range has underlined the growing sophistication of its nuclear deterrent. The official statement described Agni-4 as a medium-range ballistic missile. By the range limits usually accepted around the world, that is 3,000 to 5,500 kilometres, it fits better as an intermediate-range ballistic missile. So remember it in one simple line: this is an intermediate-range ballistic missile, sometimes officially listed as medium-range. The Agni family is the backbone of India's nuclear deterrence, and each member has a separate duty.