What is "Terminal High Altitude Area Defense (THAAD)", sometimes seen in the news?

The correct answer is C. THAAD is an American land-based, mobile anti-missile system built by Lockheed Martin under the US Missile Defense Agency. It uses hit-to-kill interceptors to destroy short, medium and intermediate-range ballistic missiles in the terminal phase, when the missile re-enters the atmosphere at high altitude.

• A is wrong: Israel's well-known systems are Arrow, David's Sling and Iron Dome. THAAD is not an Israeli radar.
• B is wrong: India's programmes are the Prithvi Air Defence (PAD) and Advanced Air Defence (AAD) systems, tested under the Ballistic Missile Defence programme. THAAD has no Indian link.
• D is wrong: Japan and South Korea have no defence collaboration by this name. Japan's missile defence cooperation is mainly with the US, including the SM-3 interceptor.

The core concept is layered ballistic missile defence: boost phase, midcourse and terminal phase. THAAD covers the terminal phase. Its deployment in South Korea from 2017 drew objections from China and Russia over radar reach, which is why it appears in Mains debates on strategic stability and India's own missile defence.

Trap: Aspirants mix THAAD with Israel's Arrow or with India's AAD, or assume the name points to a country other than the US.