Brussels — A controversial American plan to decrease allied dependence on the nuclear defense of Western Europe is picking up support among independent strategists. The plan calls for the development of a new generation of sophisticated conventional weapons and intelligence techniques. A number of nongovernmental United States and European experts, many of whom once held high military or civilian office, have given their support to this plan suggested by NATO commander Bernard Rogers last year.
General Rogers, US Defense Secretary Caspar Weinberger, and others have since tried to convince NATO members they should develop new high-technology systems to strike deep behind enemy lines and thwart a possible Warsaw Pact attack on Western Europe.
West European governments have reacted cautiously to such recommendations, which Rogers said could increase their military spending from the target of 3 percent growth per year to 4 percent.
But outside experts who have studied the Rogers plan, and an internal American document labeled ''Battlefield 2000,'' say the technology called for could be developed in the next five years for between $10 and $20 billion. They also forecast that all these adjustments together could add 1 percent to the annual growth in NATO expenditures.
The aim of such new technologies would be to deny the Warsaw Pact the follow-up reinforcements their strategy requires for rapid breakthroughs in NATO defenses.
The proposed NATO doctrine would involve the construction of some 7,000 medium-range nonnuclear ballistic missiles that would concentrate on so-called ''high-value'' Warsaw Pact targets. These targets would include about 5,000 nonnuclear missiles with so-called ''smart'' warheads capable of homing in on distant targets, about 1,000 reloadable rocket systems, missile shelters, and personnel.
They would be aimed at destroying the Warsaw Pact's 30 to 40 main operating air bases, blocking its armies' progression across some 100 strategic river crossings or other transport junctions in the central European theater, and wiping out its command and communications structure. Experts say such technologies are already in Western hands or on the drawing boards. They would have to be accompanied by advanced electronic means of target acquisition, jamming, and other deNenses against enemy attacks.
These Western strategists feel this would not eliminate the need for a NATO nuclear force or its policy of a flexible forward defense, but would lessen the NATO recourse to nuclear weapons. They reason that such a new NATO capability would be more likely to deter a surprise Warsaw Pact drive than current conventional defense, and create so many uncertainties for Kremlin military leaders they would not launch such an attack.
These Western sources also support proposed ''confidence-building measures'' such as the notification of large-scale troop movements and the establishment of a joint NATO-Warsaw Pact standing committee to exchange information, especially in crises.
It is widely felt that the most likely attack scenario would involve a surprise invasion of Soviet, East German, and Czech Army divisions into Western Europe. Such an attack, experts estimate, would require two to four days of visible preparation. It would be followed by other waves of attack designed to penetrate NATO defenses, and could quickly involve chemical and nuclear weapons.
The new NATO weapons, in the eyes of these strategists, would provide a credible deterrence to such a Warsaw Pact strategy on the battlefield or in the planning stages.
While the initial reaction to such proposals has been cool, the growing support on the part of independent experts is expected to keep the issue on NATO's agenda at future ministerial sessions. And some see them as a response to public anxiety about nuclear weapons.