Don't blow up the Iran deal. Trump's strategy is working.

The U.S. and its allies now enjoy the best of both worlds: Iranian compliance without the international investment Tehran had counted on.

European banks and businesses are wary of the Iranian market at this point. U.S. officials tell me Europe is asking for further clarifications from the Treasury Department on what kinds of investment will not violate existing sanctions. Deals that appeared to be done at the close of the Barack Obama administration — like Boeing’s multi-billion dollar aircraft sale to Iran — are now in doubt. Iran’s rial has been in free fall, losing a quarter of its value in the last six months.

There are many reasons why Iran’s economy isn’t attractive in 2018 to significant foreign investment. Its secret police keep arresting dual nationals on false charges; its proxies and revolutionary guard keep waging war in Syria and Yemen; and its banks won’t stop laundering money for the Lebanese terrorist group Hezbollah. Add to this a new Saudi-led strategy to pressure businesses not to enter the Iranian market.