Know. well the big welcome to our viewers on p.b.s. in the united states and all over the world we begin the day with escalating tensions between iran and the u.s. iran has condemned a threat by donald trump on twitter this weekend the u.s. president warned about the quote end of iran as a response tehran's foreign minister zarif used his twitter account to say quote iranians have stood tall for millennia while its aggressors are all gone economic terrorism and genocidal taunts won't and iran never threaten an iranian tribe respect it works relations of course between the 2 countries have only...