No one is taking bets on how solid the ceasefire between Israel and the Palestinians will prove to be. But the Gaza conflict has highlighted one apparently permanent change in the Middle East – the shrinking influence of Syria, stuck in a bloody and unstoppable war.

If Mohamed Morsi, the Egyptian president, is now basking in glory as the indispensable mediator between Hamas and Israel, his counterpart in Damascus, Bashar al-Assad, looks distinctly like yesterday's man.

Syrian state media focused intensely on Israel's onslaught against the Palestinians in Gaza. But Assad's Arab critics have been doing some bleak calculations: in the eight days of Operation Pillar of Defence 160 Palestinians were killed by Israel. In the same period, Syrian forces killed 817 civilians and injured thousands. Last Monday alone, says the opposition, 150 Syrians died.

Al-Arabiya, the Saudi-owned TV channel, drove home the point about double standards nicely by quoting an Israeli rabbi who publicly urged his army to "learn from the Syrians how to slaughter and crush the enemy."

Any sense that the Gaza crisis was providing a handy diversion from the global attention to Syria was shortlived.

Officially, Syria has been in the front line of confrontation with Israel for 64 years, losing the Golan Heights in 1973, the second of three full-scale wars, and repeatedly clashing with Israel in Lebanon. Five years ago, Israel bombed a suspected nuclear reactor in northernSyria.

the neighbours have also been "the best of enemies." Israeli leaders preferred Assad and his father Hafez as the "devils they knew" who kept the peace on the Golan, a quiet front until the recent spillover from the uprising and fears that chemical weapons might fall into the hands of rebels. Syria also spent eight years negotiating with Israel, though they failed to reach agreement.

But the country that used to describe itself as the "beating heart of Arabism" has also been a leading member of the "axis of resistance" – an ally of Iran and patron of Hamas and Hezbollah in Lebanon. Hamas finally abandoned its Damascus headquarters this year, unable to stand the contradiction between demands for Palestinian freedom and the brutal suppression of the Syrian uprising. In early November, the Syrian security authorities closed the Hamas offices.

Khaled Meshal, its best known leader, is now an honoured guest in Egypt and Qatar, Assad's sworn enemy. Hamas, though still shunned as a terrorist group by the US, the EU and Israel, has far more respectable, and influential, Arab friends than Assad these days.

Smaller Palestinian factions are still based in Damascus. One is the Popular Front for the Liberation of Palestine: General Command which claimed responsibility for Wednesday's bus bombing in Tel Aviv. But Palestinians living in Syria have suffered along with Syrians during the 20-month uprising.

Assad is preoccupied with his own survival. But he is not the only Arab leader facing marginalisation. Hassan Nasrallah, the secretary general of Hezbollah, has not had a good Gaza war either, praising Hamas but doing nothing to help it – and drawing attention to the fact that his organisation has not launched any of its thousands of missiles at Israel since the 2006 Lebanon conflict. Nasrallah's "resistance" credentials have also been badly tarnished by his support for Assad. Nasrallah may, some analysts believe, be keeping his powder dry in case Israel attacks Iran.

Nearer to Gaza, another big loser is Mahmoud Abbas, the PLO leader and president of the Ramallah-based Palestinian authority. Abbas's problem is not new but has been exacerbated by a war against Israel in which his Islamist rivals have, with a degree of plausibility, claimed victory.

It has also highlighted his irrelevance and exposed him to the charge that he is simultaneously too close to Israel while failing to extract any concessions from it.

It is all evidence that old Middle Eastern certainties are disappearing while the precise shape of a new regional order has yet to emerge.