The attack to Aramco on September 14th 2019 does not only destroy 2 oil facilities and descend the global oil supply but also destroys the dream of Saudi Arabia about the US security power! It is a long time that Saudi authorities believe that their close relationships with US as well as the purchase of weapons form US can protect them from any potential dangers.
On the other hand, Trump does not want to enter a new war before the 2020 election. Moreover any attack to Iran can decrease the oil output of Iran. Although Iran oil production and supply eased off significantly due to the sanctions but its elimination from the oil market is another shock for the oil price worldwide. And in response to these attacks, Iran may also start to attack to Saudi oil facilities which were not well protected by the US on September 14th! Closing the Strait of Hormuz by Iran also can increase the oil price and insurance of freights.
China will face problems regarding their energy imports as Saudi Arabia is the key exporter of oil to China. Although Europe is less dependent to Saudi’s oil, it still imports 13% of its oil requirement from Saudi Arabia.