The banner across the Command Post Pub read, "Happy Birthday Marines," but what the boys inside had in mind was a war party.

Bartender "Top" Taylor, a 27-year Marine Corps veteran, was offering for sale T-shirts that showed a picture of a U.S. Marine with a fixed bayonet pointed in the face of an Iranian cowering beside a bag of money and a barrel of oil. "How much is the oil now?" the slogan read.

As dozens of muscular, crew-cut and tattooed men lined up to pay $4.50 for Top's latest creation, other Marines sat at the bar, admiring M16 rifles that hung from the wall, washing down hot pastrami with 10-cent beer and listening to Kate Smith on the juke box singing "God Bless America" and Frank Sinatra crooning "I Did It My Way."

On the 204th birthday of the U.S. Marines, on the eve of Veterans Day, many of the thousands of men stationed at Quantico yesterday were on edge. A major had addressed the men before granting them weekend leave on Friday, warning those who ventured into Washington to stay clear of the Iranian demonstrations, "no matter what kind of feelings they may evoke."

Armed forces officials made repeated inquiried to the D.C. mayor's command center and the city police department this weekend to determine if any Marines had participated in the demonstrations. None apparently had.

"They all wanted to go up there and crack some heads," Top Taylor said. "You ask 99 and nine-tenths and that's what they want to do. That's waht they've been trained to do. For the first time since Pearl Harbor, they feel the backing from the American public. That's all they ever needed."

Moslem students had stormed the U.S. Embassy in Tehran seven days ago, taking more than 60 Americans hostages, including the ceremonial Marine guards. The students then demanded the return of Shah Mohammad Reza Pahlavi, who is being treated for cancer in New York.

For the Marines, whose tradition of patriotism takes them from the halls of Montezuma to the bow of the Mayaguez, this was an insult and a direct challenge.

"Two regiments could wipe 'em out," suggested a crew-cut Jack Shrader, 25, as he stared solemnly into his mug of beer. "But that would be bad for our image."

His buddy, Craig Nelson, also 25, recalled the Battle of Tripoli, fought in 1805, which they were studying in their war tactics class.

"Remember how Lt. Presley O'bannen took a small division of Marines and took the city, restored the rightful ruler and raised out flag in the old world for the first time?" he said.

"The shores of Tripoli," Shrader recalled. "prince Mohammed Bay was so grateful he gave O'Brannen the Mameluke sword in the city of Derna.

That's why all officers wear the sword today."

"Right," Nelson replied, "So, gimme a reconnaissance unit and a couple-of-dozen men from the special forces and we can get out people out. Then say, 'to hell with the Iranians.' You give 'em foreign aid, you give 'em weapons and they barf on your face."

It was th second time this year that Iranian students had seized the U.S. Embassy in Tehran; the second time, as the Marines saw it, that their men had to surrender their weapons without firing a shot, not knowing whether they would be killed, tortured or released.

"Bad precedent," Top Taylor said. "We're supposed to kick" their behinds.

A Glenn Miller record was playing "String of Pearls" on the juke box, setting a World War II mood, when Timothy Simpkins, 24, grabbed a plaque from a display case -- one with the slogan about how "their hearts and mind will follow."

"I hate to say it, but that's just the way some people have to be communicated with," Simpkins said. His shaved head and clear face made him seem ageless. "Now I'm for talking with those Iranians." He leaned back and cracked his knuckles.

"We can tell by the way our own public's acting that this is not going to be tolerated much longer," Simpkins said. "At the first sign that our people are being hurt, we will go in and get 'em out. We got our pride," he said.

"God damn right!" said Top Taylor. "Tell the politicans so they can know, too. Ntothing but true grit down here."