The impact of an on-again, off-again summit between leaders of the United States and North Korea leads this week's edition of Futures File, our weekly commodities roundup. North Korea tensions rocket higher On Thursday, President Donald Trump announced that he was canceling the upcoming summit with North Korean leader Kim Jong Un. This withdrawal came after North Korean complaints and threats, which Trump met with an ominous response, “You talk about your nuclear capabilities, but ours are so massive and powerful that I pray to God they will never have to be used.” Global markets reacted swiftly to the news, largely reflecting increased uncertainty and greater concerns about the prospect of nuclear war.Read more on NewsOK.com