President Obama may believe he can abandon “nation-building abroad” to focus on “nation-building at home,” but that is what he would normally call a “false choice.”

In his next term he will face major challenges abroad, not just challenges of “nation-building” but threats to our national security: an unstable and nuclear-armed Pakistan; a possible Taliban take-over in Afghanistan; a potential Iranian nuclear capability threatening vital U.S. interests in the Persian Gulf and the security of Israel; the growing strength of anti‑American Islamist extremists in Syria in the absence of meaningful support for the non-Islamist opposition.

Libya does present a challenge of nation-building, but the U.S. has already suffered a major setback -- including the murder of a U.S. ambassador and three other Americans -- by leaving the new pro-American Libyan government unable to provide for that country’s security.

Obama may wish to “pivot” away from all of these trouble spots and focus on the more promising Pacific region, but there the future challenges may be even greater. For three decades, that previously bloody region has actually been “pacific.” But tensions are rising and it will be dangerous if the U.S. is perceived as inward-looking and in decline.

True, the U.S. can’t afford to lead unless we fix our economy. But we can’t afford not to lead. And we can’t fix our economy by abandoning America’s role in the world. Our entire national security and foreign policy spending is barely one-fifth of all federal spending. Eliminating it entirely -- which is unimaginable -- would still leave us with a large and growing deficit. Some prudent cuts are possible, but they will not solve the overall problem. To fix our economy there must be a reform of “entitlement” spending. The president needs to tell that inconvenient truth to the American people.