Charles Glass is not the kind of American who was supposed to be in danger in the Middle East. He knew the area, his friends say; he had covered it from all sides, all viewpoints, even all the ideological fringes.

So why was he in Beirut, a place most American journalists have shunned in the last few years for fear of disappearing just as Glass did Wednesday morning? A man with a wife and five children in London, what was the former ABC News correspondent doing in a place where any tall, foreign-looking male seemed to stand as an invitation or even a provocation to become the latest U.S. hostage?

"Why did he go? Because he had done it before," said Peter Jennings, ABC World News Tonight anchor and a close friend of Glass. "Charlie is not naive, but Charlie is a naif . . . . He is the kind of guy who believes that because he loves other people so much, things will be okay."

Others said Glass may have believed that because the area was under Syrian control, he was safe or that he was protected by being with Ali Osseiran, the son of Lebanon's defense minister.

And a State Department spokesman said yesterday that "technically" Glass may have used his American passport improperly by going to Lebanon without getting special permission from the U.S. government.

Glass, 36, who had taken a leave of absence from reporting for ABC News to write about the people of the Middle East, has been best known for his interview with the captive pilot of TWA Flight 847 in June 1985 as a hijacker brandished a gun near the pilot's head.

Writing in the September 1985 issue of Washington Journalism Review, Glass contrasted the intense coverage of the TWA hijacking to scant coverage of Israel's taking of prisoners from Atlit in Lebanon into Israel -- two events that many believed were connected.

The friends and sources in the Beirut community who helped Glass during the TWA story may have been part of what caused him problems this time, several friends said.

"He'd been there all those years, knew so many people and was so respected by so many sides, perhaps he thought he would be safe," said Bill Blakemore, an ABC correspondent based in New York.

"A lot of the old Middle East hands are accustomed to the idea that people hearing news on another continent always think the country's in flames, while you can be there and think it is even rather pleasant at times," Blakemore said. "You can lose perspective here, but you can also lose perspective in the country where you are."

Glass, a native Californian, went to Beirut shortly after graduation from the University of Southern California in 1972 with a philosophy degree. For about four years, Glass was a free-lance reporter and sometime student at the American University in Beirut, friends said.

He was wounded during the 1976 Lebanese civil war and also won an Overseas Press Club award that year.

Moving to London to continue his free-lance work, he was editor of Near East Business Monthly in London for two years in 1979-81 before joining Newsweek as a correspondent in London and Boston.

Jennings said that he was instrumental in ABC's hiring of Glass as a correspondent in Beirut, where he stayed until being assigned to London in 1985.

In March, Glass took a leave to write a book which he has described to friends as a travel book on the Middle East and a book about the Syrians. Jennings, who said he had talked with Glass about the book several weeks ago, described it as being a travelog much like those by British writer Jan Morris.

"He's traveling with an armful of old diaries, some of which were written 150 years ago," said a distraught Jennings. "In our last conversation two or three weeks ago, he said he had stayed in the same house cited in a diary by a British diplomat and that nothing much had changed."

United Press International correspondent David Zenian reported from Cyprus that before Glass left Nicosia last month, he told friends that he would "be okay" in Beirut.

" 'I have friends there -- after all, Beirut has always been like home to me. I have written so much about the politics of the region, and now it's time I do something about the people,' " Zenian quoted Glass as saying to friends.

" 'The world thinks Lebanese are bloodthirsty warmongers . . . . Well, they are not.' "

" 'I know a lot of people in Beirut,' " Glass reportedly said. " 'And I will be okay there.' "