Realizing that the Middle East is too important to be left to others — and that neglecting it could run to China’s peril — China is no longer willing to sit on the sidelines and watch the region descend into chaos. China has for several months harbored a suspicion that the United States, entering an election year while drowning in domestic oil and gas supply, is not as interested in the Middle East as it has been for the past half century. (At any rate, Washington’s relations with Riyadh and Tehran are too thorny to enable it to be an honest broker.) More importantly, Russia has laid down the flag of Middle East neutrality that it carried for most of the post-Soviet era. Moscow once enjoyed equally good relations with Tehran and Riyadh. But in plunging into the civil war in Syria, Russia — despite the fact that most of its Muslim population is Sunni — entangled itself with the Shiite camp, and can no longer be trusted by the Sunnis. With the United States and Russia no longer able to hold the balance between Iran and Saudi Arabia, China, which has solid relations with both, is increasingly tempted to fill the vacuum.