Zbigniew Brzezinski, former national-security adviser in the Carter administration, says the Reagan administration runs grave risks in declaring that it is abandoning the unratified SALT II treaty with the Soviet Union, Monitor correspondent Daniel Southerland reports.
In a breakfast meeting with reporters, Mr. Brzezinski said that without the constraints included in the SALT agreement, the USSR could resume a strategic-weapons buildup that the United States could not match. He noted the treaty restricts both sides to 10 warheads per missile. Without the restriction, some analysts think the Soviets might place as many as 30 warheads on each of their SS-18 missiles.
Last week Secretary of State Alexander M. Haig Jr. told the Senate Foreign Relations Committee the Reagan administration had informed the Soviet Union: ''We consider SALT II to be dead.''
Mr. Brzezinski proposed each side cut its nuclear weapons stockpiles by 5 percent each year as an interim measure, designed to help maintain the arms-control process until a new strategic-arms agreement could be reached.