What's really behind Trump's surprising tweet on Iran's 'failed satellite launch'

Donald Trump has claimed that the US had nothing to do with reports of a failed Iranian satellite launch - and sent his "best wishes and good luck" in determining what happened at the site in Semnan.He tweeted: "The United States of America was not involved in the catastrophic accident during final launch preparations for the Safir SLV Launch at Semnan Launch Site One in Iran. I wish Iran best wishes and good luck in determining what happened at Site One."