Leaders of Russia and the United States are set to sign a new treaty in Prague on Thursday to reduce their nuclear arsenals, according to media reports. The plan is for each nation to reduce their active nuclear warheads to 1,500.

The international community believes that these two nations, who combined possess over 90 percent of all nuclear weapons in the world, bear unavoidable responsibilities for complete nuclear disarmament. But even after this treaty is signed, I can hardly say with any confidence that the role of nuclear weapons in the US and Russian security strategies has fundamentally changed.

It also seems like the US and Russia want to ease any pressure on them from the international community by signing the treaty before this month's Nuclear Non-Proliferation Treaty (NPT) Review Conference, which is held every five years.

Though the US and Russia have both given up a strategy of confrontation, there still is a chance that a nuclear war could erupt. The two nuclear powers have reached a series of nuclear disarmament treaties and reduced half of their strategic nuclear weapons. But the US and Russia have reduced their nuclear weapons for different reasons. For the US, security targets and its strategic strike force have changed. So has the development of conventional strike and defensive capabilities, which make it unnecessary for the US to maintain a large nuclear arsenal.

The US' nuclear arsenal also invites a great deal of international criticism. Critics have said that the arsenal undermines the international Nuclear Non-Proliferation System and creates opportunities for hostile countries and terrorist organizations to acquire nuclear weapons.

For Russia, gradual disarmament has happened because it can't maintain a large nuclear arsenal. But it insists on maintaining nuclear parity with the US considering the US' anti-missile plan in Europe.Despite their actions to pare down their nuclear arsenal, the two nations still hold nuclear weapons as an important part of their security strategies.

First, the recent treaty that should be signed is nothing new. Both sides have been disarming nuclear weapons since the early parts of the Cold War. In 1985, the US and Russia agreed in principle that they would halve their strategic nuclear weapons cache in the next five years. The new disarmament treaty only continues what they have started.

Second, the US and Russia still possess almost 10,000 nuclear warheads; about 5,000 of them are active.

Third, the treaty only changes the way they store the nuclear weapons. It neither demands completely destroying nuclear warheads and how they are deployed, nor stipulates strict inspection measures on them.