The American-made Patriot and Russian S-400 Triumf air defence systems are currently hogging international orders despite their price tags running into billions of dollars. While the Patriot has more or less a captive market within United States allies, the S-400 has had to sell on its capabilities alone having won orders from Turkey and China, countries which compete with Russia in the international arms market.

Further orders for the S-400 is likely to come from India which has internally approved the acquisition with only a formal signature on the contract awaited to set the procurement process in motion. In addition, Saudi Arabia, Morocco and Iraq are said to be in negotiations to buy the system.

Another US-made system, the THAAD (Terminal High Altitude Area Defence) missile defence system that is designed to intercept ballistic missiles at high altitude is also a competitor for the S-400 regarding some of its features, though not in terms of direct international sales.

Features of all three systems to determine relative advancement and suitability for various missions.

Quantitative analysis of the three missile defence systems:

Characteristics
S-400
PAC-3
THAAD
Max. target speed 4.8 kilometres per second (17,000 km/h; 11,000 mph; Mach 14) 1.38 kilometres per second (5,000 Km/h; 3106 mph; Mach 4.1) 2.8 kilometres per second (10080 km/h; 6263 mph; Mach 8.24)
Operational Range (km) 400 km (40N6 missile)
250 km (48N6 missile)
120 km (9M96E2 missile)
40 km (9M96E missile)		 20, PAC-3 MSE- 35 >200 km
Guidance System Active Radar Homing Inertial/Active   millimeter-wave radar terminal homing Indium-antimonide imaging infra-redseeker head
Flight Altitude 185 km for 40N6
30 km for 9M96 and 9M96E2
20 km for 9M96E		 24.2 km 150 km
Propellant YAMZ-8424.10 Diesel V12
400 HP/294kW Engine		 Single-stage solid 
propellant rocket motor with special attitude-control mechanism for in-flight maneuvering		 Pratt and Whitney Solid-fuel rocket
Warhead  directed explosion warhead proximity fused warhead No Warheads
Launchers At least eight launchers with 32 missiles and a mobile command post eight-round
Mobile trainable semi-trailer		 Consists of at least six launcher vehicles, each equipped with eight missiles, with two mobile tactical operation centers and a ground based radar
Warhead Weight (kg) 24 to 180 90 NA

Data compiled from manufacturers’ websites and other open sources.

Source>>