In short order after King Hussein's visit to Washington last month, when it looked as if fresh peace talks might get under way, a Jordanian plane was hijacked and blown up, and then a TWA flight was hijacked. One of its American passengers was killed and 40 of the American passengers and crew remain hostages in Beirut.

Can it be that the timing of these incidents was accidental? There are reasons to suspect that a war has been declared on the United States "through the impudent use of terrorism, whether by states or independent groups," as one U.S. official put it.

The sequence recalls the killing of Issam Sartawi, a PLO official who had met with Israelis, at a moment when rumors were current that Shimon Peres, now prime minister of Israel, was about to meet with Hussein. Sartawi's murder was a chilling reminder to those who might choose the moderate road.

In the TWA hijacking, 500 Shiites had already been released by Israel, and 340 more were scheduled for early release. So why hijack the plane? Who gains from the attack?

Syria is certainly one possibility, for the attack could well slow King Hussein's peace initiative, deter moderate Palestinians and open a rift between Israel and the United States.

But whatever shadowy forces are at work, there is now one flesh-and-blood figure to focus on: Nabih Berri, the Lebanese Shiite leader, a lawyer, who is known to be close to Syria and who also serves in what passes in Lebanon for a government as minister of justice and minister for the south. After the plane finished its shuttling between Algiers and Beirut, Berri reluctantly asserted control over it and its remaining passengers.

His status is indicated by the fact that the White House bypassed Lebanon's president and asked Berri to take responsibility for the fate of the hostages.

Has he bitten off more than he can chew? In a region where people flee not only responsibility but identification, he has provided the United States with an "address." He has become someone who can be held accountable for the hostages. But he has also insisted that he cannot turn over all of them without concessions. "It's either him or George Shultz," an Arab ambassador told me. "He has no free hand, and to be nice to the Americans would kill him."

The United States had hoped Berri would be more moderate than rival Shiite leaders. But now he is in a position long occupied by Yasser Arafat: he must either keep the Shiites united with the radicals or he will have to split the movement and fight the radicals. It is the difference between being a terrrorist leader and earning broad international understanding.

I spent a day with Berri while the U.S. Marines were still in Lebanon and he was briefly visiting his six children in Detroit. He likened the situation of Shiites in then-Christian-ruled Lebanon to the position of blacks in South Africa. He expressed sympathy for the Palestinians, but made clear he didn't want them to use southern Lebanon as a substitute homeland.

He insisted that although he had a good relationship with the Syrians, he was not their puppet. Acknowledging that there were posters of Ayatollah Khomeini spread throughout West Beirut, he said his followers had only religious, not organizational, ties to Iran.

That day he claimed to be the leader of Lebanon's Shia community -- a claim disputed then as it is today. Moreover, he disclaimed any Shia role in the bombing of the Marine barracks -- just as today he denies any involvement in the planning of the hijacking. Yet reliable reports link him to terrorism in south Lebanon, and he did enter into a kind of collusion with the hijackers by accepting some of their demands as his own.

Unlike the king of Jordan, who condemned the hijackers as "the scum of the earth," Berri stands to profit if the United States or Israel gives in and releases the Shia prisoners on his terms. Moreover, he stands to lose out to more radical groups if the United States and Israel refuse to succumb.

In short, if he wasn't in on it at the start, he's in on it now. One observer put it this way: "He's colluding with these people. He's a partner in crime. He gave an order, and three were released. He's interposed himself as a partisan. There's an address."

It's an address in a very tough neighborhood, as Berri has good reason to know.