While Israel is one of the loudest voices calling for a tougher line on Iran's nuclear programme, its own nuclear capability has never been put to inspection.
Israel has two nuclear research centres - at Dimona and Soreq. The latest estimates suggest that Israel has produced at least 118 warheads with weapons grade plutonium.
The Jericho ballistic missiles are capable of carrying such weapons.
The Jericho One, which is now obsolete, had a range of 500 kilometres, and could carry a 20 kiloton nuclear warhead - 20 times more powerful than the US bomb dropped on Hiroshima in 1945.
The Jericho Two has a range of 1500 kilometres. It could just reach Iran - and is believed to be able to carry a one megaton nuclear bomb, which is 1,000 times more powerful than the Hiroshima bomb.
It is believed a Jericho Three missile is now being developed - that will be able to travel around 5,000 kilometres, bringing all of Iran and Europe into its range.
Al Jazeera's Nicole Johnston reports.
Source: Al Jazeera