Iain Duncan Smith laments 'appalling demonisation' of Mitt Romney He told BBC Radio 5 Live's Pienaar's Politics that the debt situation in America was a bigger concern to the UK than the eurozone crisis. "I actually think it's bigger," he said. I think that the US is a massive and important feature because we do a huge amount of a proportion of our trade with America. He said Britain did not want "the American economy to go off the edge of a cliff." But at the same time, we can't sustain the level of debt that America is piling up with its increased deficits. He said the US deficit had risen dramatically under "the present administration." We are the biggest single investor in the United States by a long way... and visa-versa, by the way, they are the biggest of our inward investment, so America is important to us. The fact that it hasn't bounced back from this recession makes a very worrying picture indeed. Mr Duncan Smith also criticised the "appalling demonisation" of Mr Romney in British public debate. He may have faults. All politicians have faults. But this is a guy who ran a state very well. He got their debts and deficit down. He's turned around businesses. "Whatever else you may say about him, he is not stupid, and he is made out to be stupid over here," he said. Mr Romney was widely mocked by the UK media for a series of supposed gaffes when he visited London in July. He commented that the signs for a successful Olympics were not "encouraging," prompting a rebuke from David Cameron. He also described "looking out of the backside of 10 Downing Street," and referred to Ed Miliband as "Mr Leader."