It has taken more than six years, but the day that State Department officials have been waiting for has finally come. The Iranian economy appears to be teetering on the brink of collapse, thanks to a chokehold of unprecedented international sanctions. On Monday and Tuesday, Iran’s currency lost 40 percent of its value. Protests have erupted in Tehran over the skyrocketing price of food. On Thursday, the regime arrested more than a dozen people on charges of manipulating the rial, Iran’s currency. The country’s central bank can’t shore up the rial with foreign reserves because much of those reserves — stored in banks overseas — have been frozen by the sanctions.

The collapse of the rial has proven that sanctions can have deep effects, even if China and Russia are not on board. The crisis in Iran also shows that the Bush administration did the right thing when it decided to work with Europeans back in 2005 to add heft to the American embargo that has been in place for three decades.