It was “the Iron Curtain of the late Middle Ages” wrote historian Daniel Boorstin, referring to the Ottoman Empire’s blocking of European traders from working east of Cairo, Aleppo and Damascus.The consequent lack of direct trade between Europe and China was disrupted only between 1250 and 1350, when rare circumstances allowed Italian adventurers – most famously Marco Polo – to join the caravans that crossed Central Asia along the Silk Road.www.MiddleIsrael.netThe circumstances were the rise of the Mongol Empire, which stretched from the Pacific Ocean to the Danube River, and secured overland travel from Europe to the Far East.The commercial wall they took down reappeared once the Mongols disappeared, but its Ottoman builders were not alone in this reactionary venture. The Chinese at the Silk Road’s opposite end became so hostile to foreign trade that in the 15th century their emperors made foreign travel punishable by decapitation.It was the perfect opposite of the current Chinese policy, which this week made Beijing attack Washington for demanding that it cease buying oil in Iran.CHINA CHOSE insularity just when Europe chose worldliness, by sending and following the navigators who reached America, the Pacific and the Cape of Good Hope.As discussed here previously in a different context (“Jerusalem’s Orient Express,” 25 March 2017), this Chinese-European gap became fateful in 1793, when the Qianlong Emperor rejected a British diplomatic delegation’s request to establish trade relations.Dismissing as “barbarian manufactures” his guests’ display of barometers, telescopes and guns, the emperor insisted the Celestial Empire “lacks no product.”That is how China missed out on the Industrial Revolution, even after given a chance to glimpse its early buds, and that is how China condemned itself to the economic stagnation and military inferiority that ultimately exposed it to foreign rule and communist abuse.Now, an entirely different China emerges as the great champion of global trade, warning that sanctioning Iranian oil’s buyers would “contribute to volatility in the Middle East and in the international energy market.”The good news is that current Chinese leaders’ desire to avoid their forebears’ mistakes is sincere, a quest reflected in their urge to resurrect the fabled Silk Road.The bad news is that they refuse to see that Iran is to our era’s Silk Road what the Ottomans were to theirs.THE NEW Chinese interest in the outer world first led to Africa.Noticing the other superpowers neglected black Africa, China turned it into a strategic focus and soon became its largest trade partner, with African-Chinese trade totaling last year $120 billion, 2.26 times its level in 2006, according to the International Monetary Fund.Though criticized by some as a neocolonialism that boils down to extraction of raw materials and sprinkling of infrastructure projects fueled by hefty loans, from a Chinese viewpoint this policy was revolutionary. For the first time in its history, China was helping build distant nations and lands.The new Chinese worldliness then spread from Africa to the entire globe, through the Belt and Road Initiative with which Beijing plans to stretch railways, highways and bridges, and plant seaports, airports and power stations in more than 150 countries at an estimated overall investment of $4 trillion.With all these planned to straddle the historic Silk Road, along with maritime parallels across the Indian Ocean, many have come to suspect that by creating alternatives to American commerce’s Atlantic linchpin, China’s real aim is to elbow Uncle Sam as the hegemon of global trade.Such alarmism is both hypocritical and impractical. Hypocritical, because China’s overseas ventures are welcomed by its partners no less than any Western venture is by its own partners; and impractical because no Western grimacing will change Beijing’s long-overdue embrace of the outer world.The question, therefore, is what formula should guide China’s embrace of the world, or put differently: what kind of world should a newly mercantile China embrace?MORALITY AND trade are easily estranged. Even governments that try to be ultra-moral, like Norway, trade with morally problematic regimes, like Turkey, where Oslo continues shipping oil even after Ankara’s wholesale arrests of academics, journalists and artists.Avoiding such trade is impractical in three ways: economically, global commerce would be decimated if any immoral government were ostracized; morally, no scale can determine at what point a regime becomes unfit for foreign trade; and politically, cornered regimes might respond unexpectedly.In this abstract sense China is right that a policy that “will contribute to volatility in the Middle East and in the international energy market” had better be avoided. In practice, however, China’s argument does not stand, because it is made about Iran.Iran must be economically ostracized not because of its domestic conduct – appalling though it also is – but because of its assault on the very international harmony that China says it is out to enhance.Tehran obstructs what basic international harmony global trade demands.Verbally, it preaches another country’s annihilation. Militarily, it is meddling in four Arab countries’ internal affairs, deliberately destabilizing the Mideast. And religiously, Iran has sparked and inspired the Islamist zealotry that is the century’s supreme scourge.China, as its own leaders well know, is part of what Islamism targets. Beijing must therefore boycott Iran not in order to berate the ayatollahs, but in order to protect itself and the world.Ostracizing Iran will cost China little; Iranian oil accounts for hardly 3% of China’s consumption, and this is before China’s accelerating extraction of shale matures. Iran, on other hand, depends for its life on China, whose imports from Iran are nearly one-fifth of Iran’s overall exports.China therefore holds the key to the Iranian regime’s collapse. To become the world leader it evidently wants and deserves to be, Beijing should turn that key.The writer’s best-selling Mitz’ad Ha’ivelet Hayehudi (The Jewish March of Folly, Yediot Sfarim, 2019) is an interpretation of the Jewish people’s political history.