Look who's talking: US, Iran open indirect discussions to revive nuclear deal

How much the world has changed in six years. It's back to Vienna for Iran nuclear negotiators – to the same venue where a UN-backed agreement was signed in 2015. Times have indeed changed since Donald Trump walked away from the deal and tried his maximum pressure regime of increased sanctions. With Western allies forced to abide, Iran has not only retaliated by upping uranium enrichment.