Washington ? The Senate unanimously ratified a treaty Thursday that would cut active U.S. and Russian long-range nuclear warheads by two-thirds, acting as a separate nuclear crisis was building in Asia.

The Moscow Treaty, hailed as symbolizing a new era of friendship with Russia, would take missile levels to the lowest point in 50 years.

The pact calls on both nations to cut their strategic nuclear arsenals to 1,700 to 2,200 deployed warheads by 2012 — down from about 6,000 for the United States and 5,500 for Russia.

“The treaty is of critical importance to make the world a safer place,” said Senate Majority Leader Bill Frist, R-Tenn., shortly before the vote.

Democrats said the treaty would not make Americans safer because it allows the weapons to be stored instead of destroyed. But they said it was better than nothing and overwhelmingly joined Republicans in the 95-0 vote. A two-thirds majority was needed for approval.

“The treaty is a modest, positive step in U.S.-Russian relations,” said Sen. Carl Levin of Michigan, the top Democrat on the Senate Armed Services Committee.

Senators were mindful that rejection would be a harsh blow to U.S.-Russian relations at a time when President Bush is trying to persuade Russia not to veto a U.N. resolution authorizing force against Iraq.

The chairman of the Senate Foreign Relations Committee, Sen. Richard Lugar, R-Ind., said the treaty could help Bush win Russia’s support.

“It’s the reason why Russia might eventually work with the United States in the Security Council on Iraq, because they value the relationship. They understand something new and important is happening here,” he said in an interview.