It’s debatable when the world last found itself in such a perilous situation – and there are disturbing echoes of the eve of the first world war

As UN secretary general, it is António Guterres’s increasingly frequent duty to warn the major powers they are rushing towards catastrophe. On Friday, on the eve of the US-led airstrikes, it was the former Portuguese prime minister’s turn once again to raise the alarm at the latest of a series of deadlocked security council sessions on Syria.

“The cold war is back with a vengeance and a difference,” Guterres said. The difference is that it is no longer cold. American troops are already a grenade’s toss away from Russians and Iranians in Syria, and this weekend, missiles and planes from the US, UK and France flew at the Syrian regime.

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“The mechanisms and safeguards that existed to prevent escalation in the past no longer seem to be present,” the secretary general said. It is debatable exactly when the world last found itself in such a perilous situation. Perhaps the 1983 missile standoff in Europe, when a Nato exercise, Able Archer, almost triggered a panicked nuclear launch by the Soviet Union.

The level of paranoia has not yet reached that pitch, but other aspects of the current crisis are arguably more dangerous. There is less communication between Washington and Moscow and there are no longer just two players in the game, but a jostling scrum of major powers in decline and middling powers on the rise. Pursuing national agendas on such a crowded battlefield without colliding with others is increasingly hard. The precise targeting of the Friday night airstrikes was all about avoiding such a potentially catastrophic collision. But US defence secretary James Mattis and his generals were reportedly under pressure from the White House to use the strikes as an opportunity to take a swipe at Iran.

Those temptations are not going to go away, particularly after the arrival in the White House of John Bolton, a radical hawk on Iran, whose new position as national security adviser at Trump’s ear will echo what the president is hearing from Israel, Saudi Arabia and the United Arab Emirates.

In the gravitational pull of these agendas and allies, there are disturbing echoes of the eve of the first world war. It has more than a whiff of Sarajevo 1914 – with nuclear weapons looming not far off stage.

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The battle lines in Syria are far more complicated than the Balkans in the last days of the Habsburgs. The west is dominated by the regime, its Russian and Iranian backers and their various client militias. The rebels in the remaining western enclaves mix local self-defence with allegiance to various regional sponsors. Now the regime has consolidated its grip on Damascus, the survival of those enclaves is tenuous at best.

The cold war is back with a vengeance and a difference António Guterres, UN secretary general

In the north-west, a Turkish offensive has taken Afrin, and now threatens Manbij, where Kurdish units are allied with US special forces in an anti-Isis coalition. One of Washington’s biggest headaches is finding a way to preserve that coalition and mop up the last pockets of Isis resistance while trying to avoid a direct clash with its most mercurial Nato ally in Ankara. The dilemma has split the Trump administration. Former secretary of state Rex Tillerson sought to strike a secret deal with Turkish president Recep Tayyip Erdoğan and his foreign minister in February, when translators and policy aides were ordered out of the room in Ankara where the details were being hammered out. The bargain reportedly involved ceding Manbij, but when US Central Command found out, it was brusquely nixed as a threat to the Isis effort.

The continuing tension puts in doubt Centcom’s ability to use its airbase in Turkey near the Syrian border at Incirlik. It does not appear to have played a part in Saturday morning’s airstrikes.

The fight against Isis leaves the US and its allies vulnerable to other unintended consequences. As the remnants of Isis’s ‘caliphate’ evaporate, and the competition for territory and oil fields quickens among its vanquishers, US troops fighting alongside Kurds and other rebels have shot down Iranian drones and exchanged fire with Russian contractors working for a pro-regime militia.

In the southwest, a new battlefront is coming rapidly into focus. Israel has looked on with dismay as Iran, and the Islamic Revolutionary Guard Corps (IRGC) in particular, has consolidated its position in Syria, carving out a solid land link from Tehran to the Lebanese coast.

IRGC-trained Shia militias have provided the effective ground troops on the regime’s side. While Tehran has sought to put a ceiling on the number of Iranians in Syria, it has worked hard to build military infrastructure – air bases in particular.

Israel has carried out airstrikes aimed at preventing heavy arms transfers to Hizbullah and to keep Iranian-backed forces back from the Golan Heights, but it has held back from any major engagement.

“I believe Israel has suffered a strategic failure in Syria, mainly because Israel was reluctant to get drawn in,” said Ehud Yaari, an international fellow at the Washington Institute for Near East Policy said. “It was not proactive and didn’t do anything to encourage or assist the rebels.”

After losing hope of major US intervention against Assad and Iran taking place, the Israeli leader, Benjamin Netanyahu, has tried to convince Moscow to rein in Iranian military expansion near Israeli territory. So far, Russia has not used its air defences against Israeli planes, most recently last week when Israel bombed an Iranian Revolutionary Guard drone base in Homs province, despite Iranian appeals for protection. Tehran has vowed vengeance for the incident, in which seven IRGC guardsmen were killed.

“In the absence of a solid comprehensive understanding between the US and Russia, Israel and the Iranians are on a collision course,” said Yaari. “It’s getting very tricky. I haven’t felt the situation was this dangerous in years.”

The battle lines are not just geographical. The US, UK and France say they carried out the airstrikes to enforce a norm – a ban on the use of chemical weapons that has been breached only on a handful of occasions over the course of a century. The novichok attack in Salisbury in March has added to the sense of urgency, and the sense that if strong action is not taken, chemical weapons could become commonplace for the first time since the first world war.

The challenge facing the western coalition was what scale of attack would constitute effective deterrence, given that the last US airstrikes, a year ago, failed to stop the regime’s use of gas. There were voices calling for a much more expansive range of targets and goals. Emmanuel Macron has suggested that any military action should be used for other aims, including pressure on Russia and the regime to open humanitarian corridors.

However, the more ambitious the campaign, the higher the risk of escalation. Mattis fought hard to keep the airstrikes narrowly focused on the three alleged chemical weapons facilities. As a marine combat veteran he is well aware of the military logic of escalation once the shooting starts and each side strains to deliver the decisive blow.

The Russian military is equally aware of the risks, and appears not to have activated their formidable air defences when the moment came, noting that the incoming missiles had not come anywhere their main bases at Latakia and Tartus.

In the absence of a solid understanding between the US and Russia, Israel and the Iranians are on a collision course Ehud Yaari, analyst

This minuet with high explosives appears to have been successfully executed on this occasion, but that offers no guarantees it will work in the future. It has always been unclear how much leverage Moscow has over Assad’s actions, and the use of chemical weapons has been an effective tool in his crushing of rebel enclaves. Douma surrendered a few days after the chemical weapons attack.

Meanwhile, the other lines of conflict, and the extremely sharp competition to control the ground vacated by Isis will continue to draw the major actors into each other’s orbit. If Trump, with Bolton’s encouragement, walks out of the nuclear deal with Iran next month, as he has repeatedly threatened to do, Iran’s sense of threat will increase. If Tehran responds by restoring its uranium enrichment programme, it will lead to a return to a military standoff pitting the US, Israel and Saudia Arabia against Iran. Syria will be one of the battlefields, most likely the key battlefield, in which that confrontation plays itself out. As clashes between Israel and Iran mount, it is hard to see this White House staying out of the fight.

Russia may wish to absent itself from that struggle, but with so much military hardware flying around in such a confined space, the potential for accident and miscalculation rises steadily.

As the Russia investigation closes in on Trump, his deference to Vladimir Putin appears, for now, to have soured into personal hostility, fuelled by his sense of betrayal that Moscow has not kept Assad in check. It was Russia Trump warned to “get ready” for incoming missiles after the Douma chemical weapons attack, and Russia he warned would pay a “big price” for betting on Assad.

If an unforeseen and unplanned clash takes place, the commander-in-chief’s state of mind is critically important.

The absence of any check in the nuclear launch protocol that would allow any other US official to countermand a direct presidential order remains arguably the world’s scariest fact.