Since 1945, when the United Nations was founded, the Soviet Union and Russia have used their veto at the Security Council 120 times, the United States 76 times, Britain 32, France 18 and China only five.
The word "veto" is actually never used in the United Nation's charter.
For a resolution to be passed, it needs nine votes in favour from the 15 members of the council, five permanent and 10 non-permanent. These nine votes in favour must include the "concurring votes of the permanent members", the charter says.
The veto power of the permanent members has been widely criticised.
THE VETO RECORD
USSR/Russia: 120 vetoes. Only two vetoes since the collapse of the Soviet Union
US: 77 vetoes. Blocked 36 resolutions criticising Israel.
UK: 32 vetoes, 23 times with the US. All solo UK vetoes on Zimbabwe
France: 18 vetoes, 13 with the US and UK
China: 5 vetoes
The heavy use of the veto by the Soviet Union and the United States have gone a long way to discrediting the veto system.
The threat to use the veto can often sink a draft resolution. In the run-up to the Iraq war in March 2003, France and Russia indicated that they would not support a new resolution sanctioning war. As a result the US, UK and Spain withdrew their draft, and went to war without specific UN backing.
During the Cold War the Soviet Union used to veto UN resolutions almost as a matter of course.
More recently, the US has used its veto regularly to shield the Israeli Government from international criticism or attempts to restrain the behaviour of its military.
The veto and its critics
Critics of the system also point out that among those resolutions that do actually make it onto the books, not all are enforced.
The other main criticism of the veto system is that the permanent five, in effect the victors of World War II, do not reflect the geopolitical realities of today.
"Mr Nyet": The USSR's Andrei Gromyko blocked dozens of resolutions as a matter of course
Were the veto to be abolished, the majority view at the council would prevail and we might expect more resolutions passed, more situations identified as threats to world security, more cases of states being reprimanded and sanctions being imposed.
This assumes that a new, reformed Security Council would have widely respected powers of enforcement and the funds to carry out its will - the current permanent five council members supply a little under half of the UN's overall budget.
None of the existing permanent council members have indicated that want to surrender their veto. Changes to the UN's charter have to be approved by all five permanent members.
So familiar was a Soviet veto in the early days of the UN that Andrei Gromyko, foreign minister between 1957 and 1985, became known as "Mr Nyet", Mr No.
During the first 10 years of the UN the Soviet Union used its veto 79 times. In the same period China used the veto once, France twice and the others not at all.
The Soviet Union came to use its veto less and less, however.
Since the collapse of the Soviet Union in 1991, the veto has been used by Russia only twice - once to block a resolution criticising Bosnian Serb forces for denying the UNHCR access to Bihac in Bosnia and once to block a resolution on the finances of UN operations on Cyprus.
Eight of the last 10 vetoes at the Security Council have been by the United States, and seven of these have been of draft resolutions criticising the Israeli Government in some way.
Most recently, in September 2003, the US vetoed a resolution drafted by Syria that denounced Israel's threat to "remove" Palestinian leader Yasser Arafat. Washington said the resolution was "flawed" because it did not include a "robust condemnation of acts of terrorism" by Palestinian militant groups.
In December 2002, the US blocked a draft resolution criticising the killing by Israeli forces of several United Nations employees and the destruction of the World Food Programme warehouse in the West