The United States faces a number of serious challenges from abroad, including a more assertive China, terrorists, climate change, a North Korea with nuclear weapons and an Iran close to having them, and a turbulent Middle East. But the greatest threat to American national security comes from within — from our own political dysfunction.
The ongoing shutdown of the federal government is only the most recent example of this reality. It comes against the backdrop of sequestration (which cuts spending without regard to its economic consequences and fails to protect investment in the physical and human capital needed to make this country competitive over the long term) and the pending vote to raise the debt ceiling, the failure of which to pass would push interest rates higher, causing both economic growth and markets to plummet.
Some observers have noted the dangers posed to U.S. security by the shutdown, citing the furlough of federal employees who provide intelligence that helps keep us safe. This is true, but the consequences of what is going on (and not going on) within Congress and between Congress and the White House threaten U.S. national security in other, even more significant ways.