IN the old Middle East, a single overarching conflict between Israel and the Arab countries had many fronts, and it was the West’s prerogative to protect the flow of oil to the global economy. In the new Middle East, the defining conflict is a broader struggle, with multiple players seeking regional primacy.The new struggle began when former U.S. president Barack Obama initiated America’s broader withdrawal from the region, but it has intensified under Donald Trump. Obama, at least, had a vision for the region. With the 2015 Iran nuclear deal forestalling a nuclear arms race, he hoped that an easing of sanctions and faster economic growth would see Iran’s gradual reintegration into the international community. Trump, by contrast, has no strategy, and wants to disguise the U.S.’s retreat from the region, demonstrated in Syria by the betrayal of the Kurds, with militant rhetoric and massive arms exports to U.S. partners and allies in the Gulf.For its part, Saudi Arabia, the region’s wealthy, predominantly Sunni power (if one doesn’t count Turkey), has long harboured ambitions for regional hegemony, at least in the Persian Gulf and on the Arabian Peninsula, and views predominantly Shia Iran as its main rival. For the past few years, Iran and Saudi Arabia have been waging a proxy war in Yemen, resulting in huge civilian casualties and a humanitarian catastrophe.But the situation changed last month, with a night-time attack that targeted the Saudi oil industry. Several drones crossed into Saudi airspace undetected, where they launched precise attacks on key oil installations. The Saudi air defences, if there were any, seem to have been asleep, suggesting the attackers had intimate knowledge of local conditions.The attack raised obvious questions. Who did it, and how did they pull it off? The Iran-backed Houthi rebels in Yemen claimed responsibility, but they are in no position to carry out such an attack. Given the technology and logistics involved, the most plausible suspect is Iran, despite Iran’s denials. And Iran has profited the most from the strike.Saudi Arabia, after all, has been humiliated in the eyes of the world. In addition to the failure of Saudi counter-intelligence to detect the attack is the obvious fact that Saudi Arabia will lose the war in Yemen sooner or later. At that point, its hegemonic aspirations will become an even greater source of derision.And so, responsibility for the attack on Saudi Arabia almost certainly lies with Qassem Suleimani, the general who commands the Islamic Revolutionary Guard Corps’ foreign operations unit. With this attack, Iran has proven itself to be a major regional power with impressive technical and logistical capabilities and this could change the strategic calculus in the region.Iran has also left Trump looking weak. Following his refusal to respond militarily to an attack on a regional ally, Trump fired his national security adviser, John Bolton, an enemy of the Iranian regime. Trump’s foreign-policy dilettantism, his use of militant bombast to mask his lack of plausible options and strategy, seem to have played a crucial role in bringing about the current situation. His decision to abandon the Iran nuclear deal with no thought for what will come afterwards has proven to be very dangerous.But there is one other dynamic to consider. Following the G7 summit in August, there was talk of a possible meeting between Trump and Iranian President Hassan Rouhani. The attack on Saudi oil facilities came just weeks later, shortly before both leaders were in New York for the UN General Assembly, where they could have met. The question, then, is whether the attack was an outgrowth of an internal struggle between Iranian radicals and moderates. Whatever the case may be, with Saudi Arabia’s position eroding, the region’s two remaining military powers are Israel and Iran, and already they appear to be moving towards a confrontation. Israel is worried about Iran’s apparent capacity to launch precise long-distance attacks. And if that is not already a threat to Israel’s security, Iran could try to supply Hezbollah or regional proxies with similar capabilities.Were Israel to be attacked with the same precision as the strike on Saudi Arabia, the Middle East would be plunged into war on a massive scale. Sadly, that is the reality of a world in which the U.S. has abandoned any pretence of global leadership. — Project Syndicate.• Joschka Fischer, Germany’s foreign minister and vice chancellor from 1998 to 2005, was a leader of the German Green Party for almost 20 years.