The United States and the Soviet Union are in a cat-and-mouse game of weapons development pitting tank-killing helicopters against smart missiles, Gen. John A. Wickham Jr., chief of staff of the Army, said yesterday.

The four-star general told a breakfast meeting of reporters that helicopters currently have the edge but weapons now on the drawing board show promise of being able to fly over hills to destroy the helicopters hovering among the trees.

Soviet helicopters now have greater range with their missiles than the Army's ill-fated Divad air defense gun, which Defense Secretary Caspar W. Weinberger recently canceled after the Pentagon had spent $1.8 billion on the gun's development. Divad was supposed to protect tanks and troops from helicopters.

Wickham conceded that there may have been "some disconnect" between the Pentagon and the intelligence community, which saw the growing capability of Soviet helicopters to remain beyond Divad's range while firing at U.S. tanks.

"We never anticipated the helicopter would be such a powerful threat as it is today," Wickham said.

To counter Soviet attack helicopters with long-range antitank missiles, he said, the Army is developing a weapon called Fog M-fiber optic guided missile. It would carry a camera in its nose, transmitting pictures to the operator in a bunker behind the front lines.

If the Fog M camera spotted an enemy helicopter, the operator could steer the missile into the target. Wickham said the Army hopes to perfect the Fog M over the next few years and deploy it with ground units in the early 1990s.

The Army's new helicopter that is designed to kill tanks with missiles is the Apache. The Apache carries heat-sensing equipment to find tanks in the dark, and uses a laser beam to steer the missiles. The Soviet Union also has developed advanced antitank helicopters, notably the Havoc.

If the Army perfects Fog M or other helicopter-killing missiles, the Soviets can be expected to field a similar missile that would threaten the U.S. helicopter force, Wickham said.

In discussing other topics, the Army's top soldier appealed for understanding of the magnitude of the procurement challenge, saying the Army takes 4 million procurement actions a year. If it does 99.99 percent of them right, Wickham added, there would still be 400 mistakes.