-->By Paul Richter, Times Staff Writer
WASHINGTON -- As the Pentagon continues a highly visible buildup of troops and weapons in the Persian Gulf, it is also quietly preparing for the possible use of nuclear weapons in a war against Iraq, according to a report by a defense analyst.
Although they consider such a strike unlikely, military planners have been actively studying lists of potential targets and considering options, including the possible use of so-called bunker-buster nuclear weapons against deeply buried military targets, says analyst William M. Arkin, who writes a regular column on defense matters for The Times.
Military officials have been focusing their planning on the use of tactical nuclear arms in retaliation for a strike by the Iraqis with chemical or biological weapons, or to preempt one, Arkin says. His report, based on interviews and a review of official documents, appears in a column that will be published in The Times on Sunday.
Administration officials believe that in some circumstances, nuclear arms may offer the only way to destroy deeply buried targets that may contain unconventional weapons that could kill thousands.
Some officials have argued that the blast and radiation effects of such strikes would be limited.
But that is in dispute. Critics contend that a bunker-buster strike could involve a huge radiation release and dangerous blast damage. They also say that use of a nuclear weapon in such circumstances would encourage other nuclear-armed