Before India entered into the elite club with the Thursday launch of Agni-V missile, only five countries - the US, Russia, China, France and Britain - had the capability to launch nuclear capable long range missiles.
Following is the list of countries with their arsenal.
Russia: RS-24 is the future of Russian nuclear deterrence. Since it has just entered operations after put in service in early 2011, little is known with certainty about it. However, some sources say it has a range of 10,500 km.
RS-24 is said to be an improved version of the RT-2UTTH Topol-M, which has a similar range with a mass at launch of about 47,200 kg, including the 1,200 kgs of payload.The missile can carry four to six warheads.
Russia is also developing another missile that is said to be future cornerstone of the country's nuclear triad. RSM-56 Bulava is a submarine-launched ballistic missile under development. It can carry 10 warheads with a yield of 150 kilo tonnes each and has an operational range of 8,000 to 10,000 kms
US: The crux of the American nuclear deterrent is believed to be Minuteman III. It has a maximum range of 13,000 km. It is 18.2 m long and a launch weight of nearly 34,500 kg. The US has 500 Minuteman III operational missiles having their lives extended until 2020, when the Minuteman IV is expected to replace them.
The US also has a submarine-launched ballistic missile named Trident D-5 that has a maximum range of 12,000 km and has a payload as large as 2,800 kg..
The Trident E-6 is the next-generation US submarine-launched ballistic missile which will be an improved version of Trident D-5 with more advanced technology. It is planned to replace the Trident D-5 in 2030.
China: China's deep military strength is a closely guarded secret even as Beijing claims it possesses the smallest nuclear arsenal among the five major nuclear countries.
It is believed that China's main inter-continental ballistic missile is the DF-5A that has a range of about 13,000 km. It delivers a payload of 3,200 kg that can be equipped with one to three million tonnes yield nuclear warhead.
There is also a submarine launched missile called the JL-2 that is said to have a range of about 8,000 km and is capable of multiple targeted warheads.
France: It has the fourth largest strategic arsenal in the world - (after the US, Russia, and China - with over three hundred strategic warheads. France only deploys submarine launched ICBMs and has put in service a new submarine based ICBM called the M-51 with a range of about 8,000 km. It has the ability to hold six nuclear warheads.
The M-51 is believed to be 13. m long and weighs 53,000 kg.
Britain: It only deploys US constructed submarine launched ICBMs. Britain contributes towards the development of the US constructed missiles that it uses and develops its own warheads.