Anwar al-Awlaki was born in New Mexico.  He was also an operative for al-Qaeda in the Arabian Peninsula who fomented jihad in Yemen.

His terror portfolio reached the U.S. homeland: he facilitated the botched attack by the Christmas Day underwear bomber in 2009, and he may have prompted Nidal Hasan to massacre soldiers at Ft. Hood, TX.

The successful U.S. drone strike against him terminated his career as a jihadist.

Yet the strike has provoked consternation by some on both the right and the left because al-Awlaki was an American citizen by birth.  To these critics, the strike represents an "assassination" undertaken in violation of the Constitution's guarantee that no person be deprived of life without due process of law.  Even al-Qaeda has weighed in to express its concern that the successful targeting of al-Alwaki may have violated U.S. law.

If the kinetic targeting of al-Awlaki is allowed to stand, the argument goes, a dangerous precedent will be established whereby an American president can, by fiat, order the killing of an American citizen without even a grand jury indictment, much less a criminal conviction.  Due process will be a thing of the past.

Not quite.  Anwar al-Awlaki was not a criminal suspect.  He was an active combatant in a war, a willing participant in al-Qaeda's global jihad.  As it turns out, this makes a world of difference.

When they created the Constitution, the Framers drew a distinction between enforcing criminal laws and combating rebellions, insurrections, and foreign attacks.  The president's powers as commander-in-chief and Congress's war powers are not implicated by the former; they are concerned peculiarly with the latter.

Thus, if an American president -- even with congressional authorization -- utilized drone strikes in the United States in lieu of traditional due process against individuals suspected of committing criminal violations, the president would be acting beyond the power granted to him under the Constitution and in violation of the Fifth Amendment.  Note that the issue of whether the individual targeted is an American citizen is irrelevant -- the Fifth Amendment applies to "persons," not just to "citizens."

However, the constitutional calculus is not the same when attacks against the nation are implicated, as the ability to ensure the safety of the nation and its people represents one of the Constitution's chief concerns.  James Madison stressed this in The Federalist No. 41: "Security against foreign danger is one of the primitive objects of civil society.  It is an avowed and essential object of the American Union."

Indeed, the need to defend the nation was perhaps the primary reason why the delegates to the Constitutional Convention were willing to create a single executive so soon after they revolted against the British monarchy.  As Alexander Hamilton noted in The Federalist No. 70, only a single executive could supply the "energy" that was "essential to the protection of the community against foreign attacks."

The Framers debated and rejected a number of constitutional inhibitions on the war powers of both the president and the Congress.  Hamilton observed that the power to defend the nation:

... ought to exist without limitation, because it is impossible to foresee or define the extent and variety of national exigencies, or the correspondent extent & variety of the means which may be necessary to satisfy them. The circumstances that endanger the safety of nations are infinite; and for this reason no constitutional shackles can wisely be imposed on the power to which the care of it is committed.

This is something that has been recognized throughout American history. 

When faced with the dissolution of the nation during his presidency, Abraham Lincoln lethally targeted American citizens fighting for the Confederacy because those citizens were not simply in violation of domestic laws, but were also engaged in war against the Union.

Likewise, when Nazi saboteurs -- one of whom was an American citizen -- were captured after landing in the United States in 1942 to wreak havoc on our homeland, President Franklin D. Roosevelt deemed them enemy combatants, tried them in a military tribunal, and executed them -- including the American citizen.  This fate was appropriate for the American citizen only because he took up arms against the United States; an American citizen guilty of a basic criminal offense could never have been prosecuted in a military tribunal consistent with the Fifth Amendment.

The Framers recognized that when it comes to combating attacks against the nation, the powers granted under the Constitution to Congress and the president represent the primary means to protect the life, liberty, and property of U.S. citizens.

Allowing someone like al-Awlaki to wage jihad against the United States from a foreign country -- where the attack on the USS Cole was launched and where al-Qaeda continues to operate -- simply because he is a citizen undermines this core constitutional responsibility.  It unnecessarily exposes the American people to deprivation of their lives, liberty, and property at the hands of those who seek to destroy the United States under a cloak of nominal citizenship.  Certainly, the victims who perished in the attacks against the World Trade Center, the Pentagon, United Flight 93, the USS Cole, the U.S. Embassies in Kenya and Tanzania, the Khobar Towers, and Ft. Hood were never given any due process before they were murdered by fanatical jihadists.

If American citizenship creates a zone of protection around jihadists (as well as other malcontents) who take up arms against the United States, then America's enemies will have an incentive to recruit individuals who can claim American citizenship but who have no actual loyalty to the country.  This will provide al-Qaeda (and other enemies of the U.S.) with an unwarranted tactical advantage, an advantage not in any way mandated by the Constitution.

Al-Awlaki is not even the first American citizen killed in a drone strike.  In 2002, Ahmed Hijazi, an American operating with the mastermind of the USS Cole attack, Abu Ali al-Harithi, was killed by a U.S. predator drone strike in Yemen.

If indeed, as the critics suggest, the al-Awlaki strike represents the beginning of a slippery slope in which the constitutional distinction between law-breaking and war-fighting will be eviscerated, then why has that not been the case so far?  Why did the 2002 strike involving Hijazi -- a justifiable, if belated, response to the attack on the Cole -- fail to serve as the very precedent that the critics contend al-Awlaki's demise represents? 

The Constitution is more than simply the Bill of Rights -- its basic configuration protects individual liberty in a number of ways.  The constitutional authority to use lethal force against those who seek to destroy the United States and its people is a critical aspect of this liberty-protecting infrastructure.

Ron DeSantis is a veteran of Operation Iraqi Freedom and the author of Dreams From Our Founding Fathers: First Principles in the Age of Obama.