It had been the little war that wasn't there--not there on the American television screen, where one would have expected to find it. Finally, last night, after a nationally televised address by President Reagan, networks aired the first glimmer of combat footage from the U.S. invasion of Grenada.

However, the footage showed very little combat. And it was official U.S. government-approved film, photographed by the military and cleared by the Pentagon before being released to the networks midway through the president's remarks. If hostilities in Grenada are winding down, the war between the press and the White House is dramatically heating up.

Three correspondents, one from each network, and one network "pool" crew had been allowed into Grenada for the first time since the invasion early yesterday, and a military plane was to fly them back to Barbados by 5 p.m. so they could file stories for the nightly network newscasts. But at 8 p.m., when the president began his emotional appeal to patriotism, the press plane was still sitting there on a Grenada runway. It hadn't budged.

Military officials told the networks the plane couldn't take off because of excessive air traffic. But at all three networks, there was pointed speculation that this was just another facet of the administration's campaign to control the news from Grenada. The plane was held on the ground, it was theorized, so that no footage could air before the president spoke.

And network spokesmen said they found it strangely "coincidental" that even the innocuous footage shot and cleared by the military was not made available until the president's speech, thus preventing the networks from showing it until the speech had ended. Most of the film consisted of American students smiling, blowing kisses and flashing the "V" sign as they were escorted off the island under military protection. It looked like a bunch of kids coming home from camp.

NBC News anchor Tom Brokaw said from New York last night, immediately after he left the air, that he thought the administration's actions in suppressing news of Grenada were "ominous" and suspect.

"I think it's outrageous," Brokaw said. "I don't know how it can be called anything else but managing the news. Everything they've released has been screened by the Pentagon--even the most benign kind of footage. It's fairly clear they want to keep as tight a lid on this as possible."

When NBC showed the Pentagon-approved footage on the air, Brokaw emphasized to viewers that coverage of the invasion had been "tightly controlled" by the White House, and NBC correspondent Marvin Kalb during his analysis of the president's remarks accused the administration of "news management."

ABC was the first to air the footage--right after the president concluded his speech with "God bless you and God bless America"--and CBS showed it last. Before showing it, anchor Dan Rather told viewers that the film had been "shot by the Army and censored by the Army," and CBS superimposed the words "Cleared by Defense Dept. censors" over the images.

After showing the film, Rather said two more times that the government had shot and "censored" the film. The minute CBS left the air, its New York switchboard lit up with calls, some of them charging the network with being "unpatriotic" and others insisting the U.S. government would never censor anything, a CBS source said.

Howard Stringer, executive producer of the "CBS Evening News," was asked if he thought the timing of the film's release and the delay of the plane from Grenada were part of a White House plot to suppress coverage of the story. "It makes one anxious, suspicious and a touch skeptical about the administration's attitude toward press coverage of the invasion," Stringer said.

Robert E. Frye, executive producer of "ABC World News Tonight," said, "We are very concerned about the control--to use a polite word--that the adminstration has decided to exert on the coverage of the invasion. The concept of freedom of the press in this situation has not been adhered to. We have been totally blacked out."

While the president was on the air, slicing up and dishing out the old apple pie, network news executives in New York waited impatiently for news of the press plane. It did not land in Barbados until 8:45 p.m., more than 15 minutes after the president had concluded his speech.

A producer at one network said the administration's stonewalling had forced newsmen into the kind of journalistic espionage they might use in covering the activities of a hostile foreign nation, not their own. There was talk of independently shot videotape being smuggled out of Grenada, and then Barbados, under a producer's raincoat.

When, later last night, they got their first look at what their own correspondents had been able to shoot in Grenada, network newsmen were not thrilled. (The film was made available to network affiliates in Washington and elsewhere for use on their late-night newscasts.) They said it appeared correspondents had been severely restricted while on the island. One producer called the film "garbage" and said that the satellite feed included a report filed from Barbados by an Australian reporter who was telling his audience back home, "Two hundred years of freedom of the press ended this week" when the U.S. government took control of press coverage of Grenada.

There was also an unconfirmed report of a correspondent for Time magazine being "strip-searched" by military personnel at the Grenada airport.

Earlier in the day, in time for last night's evening newscast, the Pentagon released still photographs that showed a cache of Cuban arms at the Grenadan airport and Cubans posing as construction workers who were said actually to be part of the military buildup there. One network source said additional inconsequential footage from Grenada had been flown by the military to an Air Force base in South Carolina and then sent overnight via Federal Express to the Pentagon for its perusal and clearance.

Federal Express--when it absolutely, positively, doesn't have to be there right away.

On Wednesday, friction between the White House and the news media exploded at a briefing held by White House spokesman Larry Speakes, at which ABC News White House correspondent Sam Donaldson angrily protested the blackout. Speakes reportedly became furious and called Donaldson "venomous" in the shouting match that ensued.

Speakes, reached at home late last night, would not comment on any of the charges of news management.

Reagan's speech was his usual grandfatherly tour de force, one moment consoling--as when speaking of tragic U.S. losses in Lebanon--and the next moment the stern admonisher, warning the Soviets and other foes against aggression. He ended with an anecdote that had already been reported by seemingly every news source in America. "May I share something with you I think you'd like to know?" the president asked the viewer, proceeding to tell the story of Marine Commandant Gen. Paul X. Kelley's visit to a wounded marine who wrote on a piece of paper "Semper Fi," shorthand for the Marine Corps motto Semper Fidelis, "Always Faithful."

Reagan said of the commandant, "He cried when he saw those words, and who can blame him?" Reagan himself seemed to be choking up. And who could blame him? Meanwhile, at that moment, network news personnel were still gnashing their teeth over the lack of film and the White House efforts to control it.

If this is an attempt to manage the news, it is so far a stunningly successful one. It puts Nixon and Carter to shame. Future administrations will look back on it as state of the art.