ImmigrationImmigration has been an issue in the campaign dating back to the Republican primaries, but on a night devoted to foreign policy, the foreign policy that most directly affects millions of Americans wasn't even mentioned.
European financial crisisThe economies of Europe and America are intertwined through trade and finance. Home mortgage rates in the United States are based on a number derived in London's financial district. The world's largest military alliance is between Europe and the United States.
Despite all of that, neither former Gov. Mitt Romney nor President Barack Obama were asked about a financial crisis that threatens to sink a continent. What would either of them do to help stabilize the euro?
Global warmingRising sea levels are a threat to nations around the world, including the United States. Rising temperatures have caused climate change, leading to droughts in some places, floods in others, as well as violent storms all over the world.
Neither candidate was asked to give their view on whether or how to tackle these concerns.
North KoreaOne rogue nuclear nation that got only a glancing mention in the debate was North Korea. During Obama's term, long-time North Korean leader Kim Jong-il died and has been replaced by his son Kim Jong-un, who has rattled his saber by attempting to launch long-range missiles. Kim has also threatened to carry out further nuclear tests.