The past week's upsurge in violence in Lebanon is testing the resolve of American, French, and Italian troops that have been stationed in the country the past seven months to help enforce security.
It is also a challenge to the shaky Lebanese Army, which still does not have control of the nation's capital, much less outlying areas of the Connecticut-sized country.
And it is testing Israel's resolve, too - although in some ways it may reinforce the argument that Israel is the only nation both powerful enough and committed enough to secure Lebanon.
There had been a relative dropoff in incidence of violence in Lebanon during the winter months. Israel, after the exertion of the invasion, needed time to consolidate its occupation of the south of the country. The Palestine Liberation Organization and Syria also had to regroup in Lebanon's east and north. Factional enemies within the Lebanese political scene had to stop fighting one another to cope with a severe winter.
Now, with peace talks stalled and the Lebanese weather becoming more conducive to military operations, the renewed violence is taking the form of:
* Attacks on peacekeeping forces.
* Attacks on Israeli soldiers.
* Kidnapping and intimidation of Palestinian refugees.
* Pro- and anti-Syrian violence in Syrian-occupied Tripoli.
Maronite-Druze tension in the Shouf region also could erupt into fighting once again. And the presence of 25,000 Israeli soldiers deployed on a front facing 30,000 Syrians and 6,000 Palestinians is a volatile arrangement.
Of particular concern this week, however, has been a series of attacks on the 5,000-soldier multinational force. Eight Italian and five American soldiers have been injured in four separate incidents directed specifically against them. In addition, a Dutch soldier with UN peacekeeping troops in southern Lebanon was attacked and stabbed.
Since they arrived in the country last September to shore up the Lebanese Army, the multinational forces have faced few attacks. In September, an American marine was killed in an accident involving munitions clearance. In October, a bomb exploded near a US Marine checkpoint, causing only one minor injury. In February, two French soldiers were fired on as they were jogging. So far, however, no multinationals have been killed in attacks directed against them.
In Lebanon it is difficult to determine who is behind such attacks. Weapons, hideouts, and grudges are plentiful. Lebanon's national news agency quoted a government source as saying the attacks coincided suspiciously with Israeli diplomatic arguments that the multinationals might not remain committed to peacekeeping if they are harassed.
The US Marine commandant has written Defense Secretary Caspar Weinberger complaining that US marines are being ''harassed, endangered, and degraded'' by Israeli forces in Lebanon. He wrote: ''It is evident to me that the incidents between the Marines and the IDF (Israeli Defense Forces) are timed, orchestrated , and executed for obtuse Israeli political purposes.''
The commandant recommended ''firm and strong'' action from Washington to avoid further confrontations.