The United States' double blockade of Iran is trending on Chinese social media, where amused netizens are likening it to a "tollbooth."Since the U.S. and Israel launched their attacks on February 28, Iran has maintained leverage by choking off the Strait of Hormuz, through which flows one-fifth of the world's seaborne oil exports during peacetime. As the resulting oil shock drove international pressure to reopen the route, Tehran in recent weeks introduced a system to escort approved ships through its waters, in what some have dubbed a "tollbooth."The U.S. imposed its own blockade Monday—on ships departing Iranian ports—after the weekend's…