Strategic sobriety is a mode of thought that republics require as much as any other regime. Unfortunately, it is one that republics all too often discourage.

As my friend and Naval War College colleague, Karl Walling, observed in his 1999 book Republican Empire: Alexander Hamilton on War and Free Government, throughout the history of the American republic, a tension has existed between vigilance and responsibility. The former is the jealousy on the part of the people that constitutes a necessary check on those who hold power lest they abuse it. As Jefferson wrote, "it is jealousy and not confidence which prescribes limited constitutions, to bind those whom we are obliged to trust with power."

But while vigilance is a necessary virtue, it may, if unchecked, lead to an extremism that incapacitates a government in carrying out even its most necessary and legitimate purposes, e.g. providing for the common defense. "Jealousy," wrote Hamilton, often infects the "noble enthusiasm for liberty" with "a spirit of narrow and illiberal distrust."

Responsibility is the statesmanlike virtue necessary to moderate the excesses of political jealousy, thereby permitting limited government to fulfill its purposes. Thus in Federalist 23, Hamilton wrote that those responsible for the nation’s defense must be granted all of the powers necessary to achieve that end. Responsibility is the virtue necessary to govern and to preserve the republic from harm, both external and internal. The dangers of foreign and civil war taught Hamilton that liberty and power are not always adversaries. The "vigor of government is essential to the security of liberty."

This debate is alive and well today, as civil libertarians speak in terms of vigilance while the administration and its defenders stress responsibility in the face of an alien threat, a vast, foreign-based conspiracy that seeks to destroy the United States and kill its citizens. Today, as in his own time, it is certain that Hamilton would stress the importance of responsibility, believing that while we should always be vigilant when it comes to the Constitution and our civil rights, a prudent assessment of the threat created by terrorism tilts the balance toward responsibility.

Accordingly, Hamilton would be as appalled by the ideology of radical Islam, or what Walter Russell Mead calls "Arabian fascism" as he was by the ideology of the French Revolution. Both are "governed by a spirit of proselytism, conquest, domination, and rapine" constituting nothing short of a universal declaration of war. He would be appalled as well by the naivet&eacut; of our modern Jeffersons whose utopian vision denies the reality that war is a fact of international life or who fear executive power more than they fear our adversaries. Hamilton, now as then, would understand that the survival of the republic depends on developing, maintaining, and implementing the potential to make war.

Which brings us to Hamilton’s strategic sobriety: For the United States to survive and prosper in a dangerous world, he believed that it was necessary to 1) keep war at a distance by creating a "republican empire" possessing a government strong enough to deal with the exigencies of international threats, and 2) prepare for the worst, guided by prudence.

Most of Hamilton’s contemporaries considered a "republican empire" an oxymoron. The prevailing political tradition held that republics and empires were incompatible. Republics were free but short-lived because of instability arising from the presence of factions. Empires were secure, but security was achieved at the cost of freedom.

It was Machiavelli who suggested that security required republics to transform themselves into empires, as Rome had done. Hamilton agreed, but unlike Machiavelli, he sought to achieve this transformation by consent rather than force or fraud. Hamilton believed that such a republican empire, in the form of a powerful, indissoluble Union, would keep war at a distance, thus avoiding the militarization that had led to the downfall of earlier free governments.

Unlike Jefferson, Hamilton assumed that force ruled relations among nations in the New World as well as in the Old. Nonetheless, he expected that if America could survive as an independent nation, consent would replace force in the New World. In the meantime, the volatile and uncertain geopolitical situation required that America take the steps necessary to defend its rights and honor. These included the establishment of credit and a national bank, the encouragement of manufactures, and the creation of an expansible standing army and an ocean-going navy.

A crucial instrument of Hamilton’s strategic sobriety was a government capable of taking action when confronted by a threat. He firmly believed that the Constitution could not logically become an instrument in its own destruction. Hamilton makes this point most clearly in Federalist 23:

These powers ought to exist without limitations, because it is impossible to be foreseen or define the extent and variety of national exigencies, or the correspondent extent and variety of the means which may be necessary to satisfy them. The circumstances that endanger he 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 power ought to be co-extensive with all the possible combinations of such circumstances; and ought to be under the direction of the same councils which are appointed to preside over the common defense.

…the means ought to be proportional to the end; the persons from whose agency the attainment of any end is expected, ought to possess the means by which it is to be attained.

The key to exercising the power described here is a strong executive. In Federalist 70, Hamilton wrote:

There is an idea, which is not without its advocates, that a vigorous Executive is inconsistent with the genius of republican government. The enlightened wellwishers to this species of government must at best hope that the supposition is destitute of foundation, since they can never admit its truth without at the same time admitting the condemnation of their own principles. Energy in the Executive is a leading character in the definition of good government.

Hamilton gives as his primary reason for this claim that "[the executive power] is essential to the protection of the community from foreign attacks."

Hamilton believed that the president, as the only official elected by the people as a whole, had not only the constitutional but the moral responsibility to act on their behalf—in the interest of the salus populi. Hamilton rejected the claim that republican government required the executive branch’s "servile compliancy" to the legislative. The executive possesses his own constitutionally based power and is not, as some people seem to argue today, a wholly owned subsidiary of the Congress or at least "a kind of independent agency under the ultimate control of Congress."

During the Civil War, Lincoln took his bearings from Hamilton on the need for broad executive power in times other emergency. As he argued in an 1863 letter, certain actions that are unconstitutional in the absence of rebellion or invasion become constitutional when those conditions exists—in other words, "that the Constitution is not in its application in all respects the same in cases of rebellion or invasion involving the public safety, as it is in times of profound peace and public security."

In the current debate over presidential powers in the war on terror, Hamilton would come down on the side of those who argue that Congress can pass no law that restricts the president’s inherent constitutional power. He would also reject the idea that a judge has the authority to render the president—the constitutional officer responsible for security—powerless.

But even good institutions are not always enough to ensure safety. Leaders must also possess the will and courage to use them when they believe the situation requires it. Thus as inspector general during the Adams administration, Hamilton prepared for the worst case, a land war against Revolutionary France. He especially feared France because, as noted above, he believed that the French Revolution had spawned a type of war for which the United States was ill-prepared.

Hamilton was not the only member of the founding generation who believed that American independence could be secured fully only if European influence was ultimately expelled from the region. But the steps he took to ensure this outcome caused some of his contemporaries, including Adams, as well as many historians, to label him a potential dictator and military adventurer.

In fact, the war Hamilton feared did not materialize. While many credit Adams’ diplomacy for establishing peace, there is substantial evidence to suggest that the main reason a Franco-American war did not occur was mainly due to the role of chance in preventing Napoleon from carrying out his grand plan to occupy Louisiana. It could have occurred later but for the slave revolt in Haiti that diverted the army destined for New Orleans. It was Jefferson’s good fortune that Napoleon subsequently needed hard cash and was willing to sell Louisiana to the United States.

But chance is a slender reed upon which to base a nation’s strategy. Indeed, as Walling writes, "By the end of the War of 1812, Jefferson and Madison had learned the hard way, at the cost of several humiliating defeats, that Hamilton generally had been right… those policies that had seemed instruments of corruption in the hands of Hamilton now seemed the essence of prudence." Critics of President Bush might profit from this example.

Some have suggested that Hamilton was a militaristic state-builder along the lines of Frederick the Great or Bismarck. In fact he was an 18th century liberal who never lost sight of the necessity to remain within the bounds established by the Constitution. "Let us not establish a tyranny," he wrote in 1798. "Energy is a very different thing from violence." He recognized that war is the great destroyer of free government, unleashing the accidents and passions that undermine liberty, and that liberty is endangered by too little as well as too much power. His goal was to establish a republican regime both fit for war and safe for liberty.

By creating the institutions that minimize the inevitable tension between the necessities of war and the requirements of free government, the Founders bequeathed to the United States the unprecedented ability to wage war while still preserving liberty. As Walling points out, "More than anyone of his time, [Hamilton] envisioned and set in process the chain of events that would enable the United States to lead the free world against twentieth-century regimes far more militaristic and dangerous to the rights of man than Revolutionary France."

Without the institutions that Hamilton was instrumental in creating and the strategic sobriety that he taught, the United States would be hard pressed to defend its interests in a dangerous world while maintaining liberty at home. Just ask Thucydides. Happy birthday, Mr. Hamilton.

Mackubin T. Owens is an Adjunct Fellow of the Ashbrook Center and an associate dean of academics and a professor of national-security affairs at the Naval War College in Newport, R.I. He is writing a history of U.S. civil-military relations.