The Heritage Foundation and American Enterprise Institute host a Republican presidential debate on CNN this Tuesday at 8 p.m. on the subjects of foreign policy and national security. At a time when domestic issues dominate the headlines, Tuesday’s debate offers an opportunity to refocus our attention on matters of constitutional significance.

The Founding Fathers spelled out in the U.S. Constitution that the federal government must provide for the common defense. Yet defense spending has fallen below its 45-year historical average. It is projected to drop to 3.4 percent of gross domestic product in just a few short years.

Presidential candidates will have an opportunity to share their thoughts on this trend Tuesday night. It should be a timely topic with the Joint Select Committee on Deficit Reduction expected to announce its plan — or lack thereof — by Wednesday. Democrats have already suggested that it wouldn’t be bad thing if automatic cuts to defense were trigged by the lack of a deal.

In anticipation of defense cuts, last week the Foreign Policy Initiative, American Enterprise Institute and Heritage warned that the future of America’s national security hangs in the balance. Heritage has strongly advocated for the Super Committee to fully fund defense or risk a dangerous readiness crisis.