The United States would lose a war with the Soviet Union in Europe or the Persian Gulf if it followed any of the military plans now in hand, Rep. Newt Gingrich (R-Ga.) said here today at a conference of military officers and defense specialists.

Not one of the 100 specialists, which included a dozen generals, rose to dispute Gingrich's contention during discussions stretching over three days on what should be done to change military plans, tactics, forces and weaponry.

One Army general, whose job is to assess Soviet capabilities, said, "We can't win quantitatively with the forces we have today."

Gingrich, a leader in the group of senators and congressmen known as the Reform Caucus which is demanding changes, said both in formal speeches and interviews that the military must figure out a way to win a war with the Soviets or face the prospect of dwindling political support for its budgets in peacetime and possible humiliation in war.

Gen. E. C. Meyer, Army chief of staff, did not address the win-or-lose strategy but did say in a speech Friday night that the Joint Chiefs of Staff must be reformed to assure success of American forces on any future battlefields.

"We just are not organized to go to war when the big one happens," said Meyer. He is calling for a strong chairman of the joint chiefs who would have the power to direct strategy and decide priorities rather than be limited to chairing a deliberative body of the heads of the services.

Meyer was praised by Gingrich and his allies for allowing West Point to be the site of discussions on their movement and legitimizing it by addressing the gathering.

"The reality is that in a serious war with the Soviet Union on the Eurasian land mass there are no current plans which change the verdict that if the Russians are serious, we lose," Gingrich said in an interview. "That has to be addressed with grim honesty."

Gingrich described that reality, which he said had been confirmed to him in official military briefings, as the driving force behind the reform movement both inside and outside the military services.

When a reporter asked the group at large if anyone believed that Gingrich was overstating the situation, no one spoke up. It was at this point that the Army general who assesses Soviet capabilities, whose quotes may not be attributed without permission under the rules of the conference, asserted that the Soviets had a decisive edge.

A Marine general at the conference said his forces would fight well wherever and whenever they were sent. But he, too, stopped short of claiming that there were any plans in the Pentagon that would bring victory over the Soviets in a conventional land war.

A retired Army colonel and former teacher at West Point rose from his seat to ask "What is winning?" and to point out that current U.S. forces, whether capable of defeating the Soviets or not, continue to pose high risks in the view of Soviet leaders. "Maybe we're winning," he said. "They haven't invaded Europe."

But another Army general said in an interview that perhaps it was time to tell the public that there was no way to win a land war against the Soviets today with the forces in hand. Army leaders, he said, have been reluctant to say this forthrightly for fear of emboldening the Kremlin.

"Maybe we should come right out and admit it," to force decision-makers to focus on what to do, he said.

Brig. Gen. Del Jacobs, an Air Force planner, said his service does not share the Army gloom.

"We are in the strongest position that we've ever been in when it comes to tactical aircraft," said Jacobs. He said American planes, pilots and tactics are superior to the Soviets' and growing ever more so.

But Jacobs acknowledged that his optimism was based on the assumption that the Soviets would not find a way to blow up North Atlantic Treaty Organization airfields in a war.

In one-on-one conversations, some younger officers at this Army bastion grumbled about the pessimism of their elders.

"We've got to fight smartly," said Capt. Tony Coroalles, who has commanded rifle companies in three different Army fighting outfits. "The weapons are too lethal today for any free movement of Russian armor. I think we could win."

And a lieutenant colonel who has studied in the Soviet Union said Russian military leaders are confronted with at least as many problems as their American counterparts when it comes to fighting a conventional land war in Europe. "Neither side could win," he said, predicting that land battles would soon escalate to nuclear warfare, which would destroy whatever the combating forces were trying to gain.