hortons doughnuts. canada, in terms of its reliance on the oil industry, it is not venezuela or norway. how much of an effect will it have on that relatively diversified economy moving forward? richard it has had a pretty big impact. the back of canada has been easing -- the bank of canada has been easing monetary policy. a bigmmodity prices are headwind for canada. brendan: all the progress mexico had been making. are we learning that they are all just commodity-based economies? richard: that is the thing. when everything is growing, you talk about diversification. when the tide goes out, you see who is swimming naked, as warren buffett said. tom: when does the margin call start? , a lot ofe group blather about the singapore trading company, glencore. when to the commodity called -- margin calls start happening? , when for u.s. e&p's banks come back to these companies and say, we need to reevaluate these credit lines, oil has had a dramatic move, we need to read extend the amount of credit -- that happens in october of this year. , iyou don't see a pullback would expect production to remain resilient. tom: you have to leave the set. you are driving the price of oil down. [laughter]

. >> coming up next, richard horton examines president truman's decision to drop the atomic bomb on hiroshimand nagasaki. he looked at the promises franklin roosevelt made during the yield a conference. richard thornton is the president at the institute for the study of strategy and politics which is to dissident. this is a portion of a symposium that focused on august, 1945 in asia and the pacific, marking the 70th anniversary of the end of world war ii. it's about one hour. >> today, we have professor thornton from george washington university. he is a presidential historian and he has written books on the presidency of carter, nixon and reagan. also a book on truman and the korean war, which today, he's going to discuss truman and the end of world war ii. mr. thornton: although there are many books on truman's decision to shop the atomic bomb, there are two overarching determinations. one is the official view that it was done to shorten the war and save