London — Britain, the United States, Syria, and possibly Israel face urgent choices in the growing crisis over the terrorism conviction here of Jordanian Nezar Hindawi. Over the weekend, Syria's official media suggested there should be widespread Arab reprisals against Britain for breaking diplomatic relations with Syria on Oct. 24 and insisting on the departure of Syrian Ambassador Loutof Allah Haydar and his staff within a week.
Damascus closed Syrian airspace and sea ports to British aircraft and ships, obliging British airlines to make costly detours en route to south and east Asia.
Hindawi's 45-year prison sentence is a record for a British court in modern times. The two-week trial prompted the diplomatic break and British Foreign Secretary Sir Geoffrey Howe's accusation of ``overwhelming and conclusive evidence'' of Syrian complicity in Hindawi's effort to plant a bomb on an El Al flight here last April.
Syrian President Hafez Assad and Ambassador Haydar insist on their innocence. They contend that Israel fabricated a plot to ``set up'' Syria in the London case. Syrian spokesmen make similar charges about a case in which Hindawi's brother is to stand trial Nov. 17 for a West Berlin bombing last March.
Syrian media calls for anti-British reprisals spurred the Foreign Office to strengthen security for British nationals and properties overseas. The Foreign Office said Syria has promised to respect international conventions over the safety of about 250 Britons still in Syria.
At virtually all levels of government and the opposition, British spokesmen are urging Washington and West European capitals to acknowledge the guilt of Syria's intelligence services in terrorism and follow Britain's lead in taking diplomatic or economic sanctions against Syria.
But after the Oct. 24 withdrawals by the US and Canada of their ambassadors in Damascus, Western nations face a series of choices -- none of them easy:
Extreme hawks and supporters of Israel in the US have often urged that both the Reagan administration and Israel should punish Syria, as the US did Libya last spring, with military attacks.
Other voices, more numerous, call on Washington to follow London with a full break in diplomatic relations and the consequences that would entail. (Washington announced Friday it was withdrawing its ambassador to Damascus.)
Other commentators and officials are urging caution. Critics of Prime Minister Thatcher believe Britain may have overreacted and that the break in diplomatic ties might make it more difficult to reopen the ``peace process'' which the Reagan administration pursued but virtually abandoned by the start of this year.
The first course -- military attack -- seasoned Mideast analysts say, might well unleash a new Mideast war, with possible superpower involvement. Unlike Libya, where Soviet missiles and radar crews left their posts and took cover before US attacks, Syria is protected by a highly sophisticated, Soviet-supplied air defence system with at least a few Russian fingers on the trigger.
In a war scenario, Israel would probably move against Syrian forces in Lebanon and opposite the Israeli-occupied Golan Heights. Such an action, or even a US break in diplomatic ties with Syria, analysts say, would endanger French, American, and foreign hostages in Lebanon.
President Assad's defense minister, Gen. Mustafa Tlas, and senior intelligence aides have reportedly long been under orders to do all they can to rescue the Western hostages. Since 1983, at least four Americans -- educator David Dodge, the Rev. Benjamin Weir, the Rev. Lawrence Jenco, and television newsman Jeremy Levin -- were released from captivity with Syrian help. Syria helped defuse the June 1985, TWA hijack crisis in Lebanon and secured release of those hostages. Assad's orders to his military could change if the US escalates pressure against Syria, observers say.
Lacking financial leverage, however, since the US Congress cut off the modest economic aid program to Syria years ago, the Reagan administration might choose to pressure the Pecten Oil Company, a Shell Corporation affiliate, to withdraw from Syria. In partnership with Syria's national oil company, Pecten recently began to pump undisclosed amounts of light crude oil. This could bring foreign earnings of up to $5 million yearly for Syria's defense-burdened economy within a few years. And the Pecten oil strike would reduce Syria's dependence on Iran.
More than 50 Americans and their families work for Pecten in Syria. As the the Carter and Reagan administrations learned in trying to get US oil companies out of Libya, Pecten might prove unwilling to withdraw and break up its partnership with Syria. For similar reasons, France, Italy , and West Germany, it is thought here, may hesitate about further economic or diplomatic measures involving their interests in Syria. Excerpts from Howe statement, Oct. 24
``There is conclusive evidence of Syrian official involvement with [Nezar] Hindawi. . . :
Hindawi spent some time in hotel accommodation reserved for Syrian Arab Airlines crew.
Hindawi spent the night after the bombing attempt in Syrian Embassy accommodation, where his hair clippings and hair dye were found.
Certain facts are undisputed:
Hindawi traveled on an official Syrian passport in a false name.
Hindawi's visa applications were on two occasions backed by official notes from the Syrian Foreign Ministry.
Hindawi met the Syrian Ambassador, Dr. Haydar, in his embassy after the discovery of the bomb.
In addition we have:
Independent evidence that the Syrian Ambassador was personally involved several months before the commission of the offense in securing for Hindawi the sponsorship of the Syrian intelligence authorities.
And we have equally compelling evidence that during his detention Hindawi sought to contact secretly Syrian intelligence officials in Damascus with a request for their assistance in securing his release.''