Can a new Middle East war be avoided amid rising tension in the Levant?

Lebanon and its six million people are a complex mosaic in which Christians and Sunni and Shia Moslems share power. The president must be a Maronite Christian, the prime minister Sunni and the speaker of parliament Shia.

It is a country where the 1975-1990 civil war that claimed more than 150,000 lives remains vivid for older people and a chilling reminder for everyone how easily conflicts can erupt.

That is at the forefront of the Lebanese as they contemplate the brutal civil war in Syria, that lies on the eastern and northern border, which has killed more than 450,000 people since it began in 2011.

Syria's regime of Bashar Al-Assad has secured more than two thirds of the country, thanks to support from Russia and Shia Iran. Assad is an Alawite, a Shia sect.

And it is the Teheran element that troubles many Lebanese most as Iran seeks to secure an arc of influence all the way to the Mediterranean.

That is part of the great competition for regional hegemony between Shia Iran and Sunni Saudi Arabia, a religious split that has grown prominent since the 1979 Iranian revolution and growing Shia ambition.

Israel has been fairly public in saying it will not tolerate Iranian bases in Syria, being established potentially for attacks against the Jewish state.

And it can count on unquestioning support from President Trump and Saudi Crown Prince Mohammed bin Salman who unite in seeing Iran and its nuclear ambitions as the great enemy.

Were Israel to attack, Iran would likely involve Hezbollah, the Shia military and political group based in south Lebanon which has also been fighting for Assad in Syria.

Many Israelis consider a two-front war inevitable, sooner rather than later before Hezbollah can supplement its formidable missile armoury with its own-produced precision missiles.

Russia has cautioned its Iranian allies but has not condemned Israeli air raids in Syria on Iranian supplies destined for Hezbollah.

Another war is too awful to contemplate as one sits in Beirut. Israel has said in such a conflict it would regard Hezbollah and Lebanon as one and the same.

No less troubling is that since the 2006 Hezbollah-Israel war the Shia group has been much more heavily armed by its Iranian patrons and sits on a veritable arsenal pointed at Israeli cities.

That Israeli concern may be reinforced politically in the May 6 elections. The introduction of a form of proportional representation and redrawn constituency boundaries are likely to boost Hezbollah's power in parliament.

The greatest fear among Lebanese political and military experts is that an Israeli attack could trigger an uncontrolled chain reaction across the region.

Away from conflict, the domestic challenges in Lebanon are huge. An estimated 1.5 million Syrian refugees have now sought refuge from the civil war there.

They supplement some 320,000 Palestinian refugees who already stretched Lebanese resources. The halving this year of US aid to UNRWA, the UN agency for Palestinians, and Washington's bar on use of any of its money in Lebanon and Syria has dismayed relief workers.

To visit Syrian and Palestinian refugee camps softens even the hardest hearts, no matter from which side.

It is heartbreaking to meet small Syrian children, traumatically ripped from normal lives, struggle to learn in a new country. Schools in Lebanon use either English or French or both as the medium of instruction in various subjects as well as Arabic. Syrian children learned only in Arabic and even then have accents that their small peers often mock.

Many have lost years of education while parents are stressed and worried over their children, the chance of work and looking into the unknown.

But sympathy is running out. Across Turkey, Lebanon and Jordan, the countries with the largest number of refugees, there is growing political pressure for them to return home.

Government officials are placing many obstacles in staying, rejecting residence permit renewals and telling them it’s time to go home.

That is understandable as resources are overwhelmed and refugees are a negatively-branded commodity.

It is easy to label people as “refugees”.The reality is many are no different from hard-working non-political families in Glasgow or Aberdeen whose lives are suddenly ripped apart.

But the Lebanese are resilient, optimistic people as they had to be during the civil war.

In the northern port city of Tripoli, as they sit smoking shisha pipes in the central square, men discuss a bright future.

They argue a huge Syrian reconstruction effort must some time begin and, Insha'Allah, their town's economy will boom as a key supply route.

But that cannot disperse the current cloud hanging over Lebanon and its neighbours: can a new Middle East war be avoided amid rising tension in the Levant?