* On first day of Eid holiday, at least 70 killed
* Death toll lower than normal, but peace elusive
* Both sides seem determined to fight for victory
* U.N. envoy Brahimi hopes truce can be built on
LONDON, Oct 26 (Reuters) - Lakhdar Brahimi's holiday truce may have saved Syrian lives on Friday, as government troops and rebels drew breath on several fronts - though dozens still shed blood on Eid al-Adha, the Muslim Feast of Sacrifice.
The U.N. envoy, discreetly downbeat since he succeeded a disillusioned Kofi Annan two months ago, could scarcely be surprised at ceasefire breaches that included tank fire and a car bombing; two previous attempts to end the conflict over the past year both quickly descended into ever more bitter fighting.
But more troubling for Brahimi, the Algerian troubleshooter called on to mediate in a civil war that has divided the United Nations, may be that when compared to the ceasefire attempts in January and April, each side seems even less ready now to talk.
``Brahimi faces an impossible task because both sides are still convinced that they can win and are determined to press every advantage,'' said Syria expert Joshua Landis, associate professor of Middle East Studies at the University of Oklahoma.
Veteran dissident Fawaz Tello, now in exile in Germany, put it bluntly - mediation focused on forming a transitional unity government might have been possible a year ago, he said: ``But after all this blood, all this sectarian conflict, it has become impossible. So now it's a battle - and one side must win.''
Nonetheless, perhaps counting on weariness of war, the envoy is seeking ways out: ``We hope this Eid in Syria will be calm, even if it is not a happy Eid,'' Brahimi said earlier this week.
``If we do find that this calm continued through the Eid, we will try to build on it. If that does not happen, we will try nevertheless, and work to open the path to hope.''
The past 12 months can give him few grounds for optimism; last year on the first day of Eid, which marks the end of the annual haj pilgrimage to Mecca and recalls the readiness of Abraham to sacrifice his son to God, 13 deaths were reported - mostly protesters shot by President Bashar al-Assad's forces.
On Friday, opposition activists reckoned at least 70 were killed across Syria, over a third of them soldiers - but that toll was lower than the daily 150 or 200 deaths that are now typical.
Between the last and present Eid, a three-day festival that for Muslim families should be the celebratory highpoint of the calendar, a time for gifts and children, two major peace drives have collapsed; rancour has only spread - not just within Syria, where religious sectarianism is driving fear and hatred, but also abroad, notably between Russia and the Western powers.
``We are not celebrating Eid here,'' said a woman in a besieged Syrian town near the Turkish border, speaking above the noise of incessant gunfire and shelling on Friday. ``No one is in the mood to celebrate. Everyone is just glad they are alive.''
THIRD PEACE ATTEMPT
The Arab League, dominated by Sunni Muslim leaders who view Assad as a pawn of their Shi'ite, non-Arab regional rival Iran, pressed the Syrian leader just before the last Eid al-Adha to accept a peace plan; it called for an end to violence against the demonstrators who had taken to the street during the Arab Spring of early 2011 and for the release of political detainees.
But though several dozen observers from the Arab states finally arrived in late December to monitor compliance with the plan, they found themselves unable to change much on the ground - indeed they were themselves harassed in some places, not least by opposition supporters angry at the League's hesitations.
Within weeks the Arab monitors were gone, and Annan, the former U.N. secretary-general, was charged with a joint U.N.-Arab League mission to try and do better. In April, he described a truce that followed his promotion of a six-point plan as ``a rare moment of calm''. But the rebels, a disparate collection of groups who were then growing in strength, were deeply sceptical.
Less than four months later, Annan quit - as much, it seemed, in frustration at what he called ``finger-pointing and name-calling'' among the big powers on the U.N. Security Council as at the spread of massacre and counter-atrocity across Syria.
That paralysis abroad, in contrast to last year's speedy, U.N.-approved and NATO-led offensive to oust Muammar Gaddafi in Libya, also shows little sign of movement, as Brahimi tries to find a new way forward on what at least one senior Western diplomat reckoned at the outset was a ``mission impossible''.
The Security Council rallied behind a call for an Eid truce this week. But Russia and China, determined to block any further precedent for U.N. military support of popular revolt, have made clear they will veto any Western push to try and force Assad out. And while U.S. allies in the Gulf offer discreet aid to the rebels, few foreign governments seem keen for deeper involvement in a war whose outcome seems destined to be messy.
Meanwhile, 20 million Syrians suffer. The government said it would hold its fire over Eid but respond if attacked. It blamed ``terrorists'' for a car bomb that killed at least five people near a children's Eid playground in Damascus. Rebel supporters blamed Assad's agents for the blast, in an opposition bastion.
One group of rebels near the Turkish border said a sniper killed one of their men on Friday: ``There's no Eid for us rebels on the frontline,'' said local rebel commander Basel Eissa.
``The only Eid we can celebrate will be liberation.''
Religious sentiment may have a history of being called upon to halt the march of war - witness the famed ``Christmas Truce'' in Flanders in 1914 - but holy day distraction has as often been a moment to attack - such as Vietnam's Tet offensive or the Yom Kippur war - and, as seen in the slaughter that followed that World War One ceasefire, a brief lull is no harbinger of peace.
Nonetheless, Eid has given Brahimi an opportunity to remind Syrians he is still active: ``After the collapse of Annan's mission, Brahimi decided to push for the lowest common denominator - a truce on the holiday,'' said Joshua Landis.
``He knew the chances of success were very low. But perhaps his efforts, even if not a success, will lift the spirits of Syrians in some small measure, as they will be reassured that the world has not forgotten them and their suffering.''
Opposition activist Tello suggested Assad's troops were using any ceasefire to rest in some areas while pressing on with attacks elsewhere; and a lack of central control among the rebel forces, he said, ensured any truce would be patchy.
For Brahimi, he said, ``This ceasefire is a way to see if the two sides, and especially the regime, is tired and wants to have a break. Because he has no plan, it's a good start.''
But, Tello said, negotiation could no longer end a war in which the opposition was ``fighting with our backs to the wall'', fearing death, prison or lifetime exile from any settlement that left power in the hands of Assad, or a state administration now dominated by his fellow minority Alawites.
``Brahimi and the United Nations are just trying to push everything to the point they desire, where we are very weak and we accept peacekeepers ... and somehow keep some of the regime,'' he said. ``We are not going to accept,'' he added, comparing rebel goals to the unconditional surrenders that ended World War Two.
Such uncompromising positions have raised the stakes for Brahimi, whose spokesman last week made clear an Eid truce was only a first step and referred to the previous peace plans: ``We cannot afford to fail a third time ... He is exerting every effort that is humanly possible to set up the building blocks to create a comprehensive initiative ... He is brutally conscious of the fact that there are hundreds of people dying every day.''
For Landis, the enmities mean Brahimi's chances of brokering a settlement seem some way off: ``Nevertheless, his efforts are necessary,'' he said. ``Some day the parties may be ready to talk, and the U.N. must be there and ready to act as a go-between.
''Only the U.N. has the legitimacy for this task.``