There is a tendency when debating issues of international consequence to prejudice against the present in favour of a more virtuous past. We persuade ourselves that there was a time when our leaders were far-sighted statesmen, people of stature and vision, rather than grubby politicians driven by the same tawdry domestic and electoral considerations that motivate our current crop of elected and appointed government officials. I search in vain through our history for those statesmen.

A case in point is George Marshall, the ascetic five-star general, Chief of Staff of the Army during the Second World War, Secretary of Defense and Secretary of State in the Truman Administration, awarded the Nobel Peace Prize for his development of a plan for postwar European reconstruction. Time magazine named him Man of the Year in 1943, terming him ‘Civis Americanus’. Marshall is widely admired in civil-military circles for saying he had never cast a ballot. And yet, when President Truman informed Marshall he intended to support the creation of the state of Israel, Marshall expressed his objection saying he wouldn’t vote for Truman if he did. So not even that patron saint of statesmanship was above politics and politicking.

Nor should political leaders in free societies soar above the surly bonds of domestic attitudes. Leaders in free societies are rightly bound to public support for their policies. It is the essential accountability of those who govern in the name of the people. It also makes democratic societies more reliable allies. There is no substitute for winning the political argument for leaders in free societies, and it makes their commitments more durable when tested by adversity.

But there is another reason, a rationale of our own civic virtue, that should motivate us to blow away the mists of untrammeled statesmanship from our predecessors. It has been best expressed by revolutionary era historian Joseph Ellis, author of both Founding Brothers, and His Excellency George Washington. Ellis insists that by carving America’s political founders out of marble rather than acknowledging their flaws and frailties, Americans exonerate themselves from doing the important work of their time. In averting their eyes from the tawdry politics, blatant self-dealing, and moral failings of those great men, they risk excusing themselves for not meeting political challenges with the necessary dedication and creativity and fortitude. That is, contemporary observers make themselves comfortable holding past figures to a higher standard than they hold themselves.

It is especially true of the United States that its history does not provide such statesmen. The very best of its political leaders considered themselves tightly constrained by public attitudes and expended considerable effort to bring the public along. Foremost, of course, is Abraham Lincoln, the Great Emancipator, who led the nation through its most trying crisis by initially denying that abolition of slavery was the basis for the Civil War and drawing the Union cause ever more committedly toward it. Lincoln began the war arguing ‘we must not interfere with the institution of slavery in the states where it exists’. By 1865, his inauguration speech rang with condemnation of slavery as the cause of the war: “if God wills that it continue until all the wealth piled by the bondsman’s two hundred and fifty years of unrequited toil shall be sunk and until every drop of blood drawn with the lash shall be paid by another drawn with the sword as was said three thousand years ago so still it must be said ‘the judgments of the Lord are true and righteous altogether’”.

America was astonishingly lucky to elect Lincoln to captain its national ship through the civil war (it is practically a proof of Bismarck’s quip that God has a special providence for drunks, babies, and the United States of America). And while there have been other good, and even one or two great, American presidents, mostly it has been governed by mediocrities – and even a few dangerous renegades.

My favourite description of Americans comes from British historian Bertha Ann Reuter, who wrote ‘Americans are a people too radical either in religion or politics or both, to live peaceably in their original home.’ Nor is early twentieth-century satirist HL Mencken far off the mark with his derisory description that ‘Congress consists of one-third, more or less, scoundrels; two-thirds, more or less, idiots; and three-thirds, more or less, cowards.’

It is important to keep in mind that the American political system was designed by people who feared government. Power is distributed among three co-equal branches of government; the two houses of Congress have distinctive functions – even the responsibilities of leading the nation in war are divided between the executive and legislature. It was designed to do nothing without consensus. To jealously guard against use of governmental power without political consensus, and even with consensus if public attitudes traduced fundamental rights. So to an even greater degree than most other free societies, America’s role in the world depends on winning public support.

In addition to the structural argument, there is another reason American internationalism depends on public support, which is that the United States won the geopolitical lottery: its territory is vast, bounded by oceans on two sides and friendly neighbours in Canada and Mexico. It merits mention that the US has not been a great neighbour to either Canada or Mexico, having wrung territory and sent extra-legal military expeditions into both. And that is before reckoning with its history toward Native American nations.

Having few and good neighbours means that the US has had the luxury of ignoring much of international relations. It also has a dynamic economy that relies less on international markets and inputs than do most developed economies. The US simply has a wider margin for error in international relations, politically and economically, than most countries, and that means other states will be preyed upon or feel the effects of international disturbance sooner than it will. They are not natural internationalists, because they have the luxury of being provincial.

America’s geopolitical circumstances also mean that in order to motivate Americans to care about the world, it is difficult to win the argument on strategic interests. Because no state can sustain policies that are fundamentally incongruent with what the nation is as a political culture – and that means confronting that Americans are a people extreme in politics and religion, difficult to persuade to care about the world. What motivates Americans to care about the world is values: the truths we hold to be self-evident.

Americans want to defend religious and political liberty because it is who they are. They want to create an international order of states that believe people have inherent rights and loan them in limited ways to governments for agreed purposes. For geopolitical reasons, the US is a reluctant hegemon, but one strongly motivated to the creation of an international order that is a macrocosm of its domestic political order.

Thomas Wright has an interesting assessment in his book All Measures Short of War that there is no point in the US adopting a policy commitment not to pursue regime change in China, Russia, or other authoritarian states. Wright considers the normative momentum of US policy to be so deeply ingrained that no authoritarian state should believe such a declaratory policy, because it cannot be true that a state constructed as the US could insulate its policy from working toward the democratisation of repressive regimes.

International relations theory is mostly a parlour game that is neither descriptive nor predictive of what actually happens in the world. It is least persuasive when arguing that all nations behave similarly irrespective of their unique histories. The United States cannot sustain a policy for long that affronts its values – this is where realpolitik as both descriptor and predictor of US policy runs aground.

Values have become an increasingly central element of US foreign policy over time. It is endearing, actually, that as America has grown more powerful, it has also grown more idealistic. Historically, the arrow tends to go the other direction: as states become more powerful they become more ruthless. The direction of travel of US foreign policy also validates that the country is capable of grand strategy (a subject often debated in strategic studies about a country so fissiparous and disputatious).

And that grand strategy, evident at least since 1918, is to make the world safe for democracy. The US feels most secure when surrounded by states similarly constituted. It is an ideological conceit, but there is data to back up the argument: democratic states fight a lot of wars, but they tend not to fight each other. It is difficult to think of examples beyond the Cod Wars between Britain and Iceland – and it is instructive of the norm that democracies compromise rather than fight each other that Britain capitulated to a much weaker power.

The political culture that motivates US power in shaping the order also restrains its use, particularly where allies are concerned. There is a wonderful example during the 1958 Berlin crisis: President Eisenhower sent his Secretary of State, John Foster Dulles, to Bonn to assure German Chancellor Konrad Adenauer that the US would actually carry out its policy of quickly escalating any conventional conflict with the Warsaw Pact to a general nuclear war – a policy designed to spare Europe becoming a battlefield. Adenauer’s response: ‘Good God, no! Not for Berlin.’

The US is often more willing to fight than are its allies, even when their own security is at stake, a cultural characteristic likely resulting from a political and religious extremism, a frontier mentality that looms large in American self-conceptions, and having little historical experience of surviving through occupation. Nor is the bellicosity of the US necessarily detrimental to allies: more Americans are willing to risk their children – the young men and women who fight their wars – to defend Germany than Germans are willing to defend Germany.

Where these proclivities lead the US, and its allies of the ideological West (which incorporates countries of the geographic east, such as Japan, Australia, and South Korea), is to a continuing grand strategy of democratic expansion: a strategy of taking opportunities to incentivise through assistance and attention and potential security guarantees an international order that advances freedom. Because they cannot persuade people to shoulder risks and burdens, whether aid expenditures or wars or simple diversion from the work of improving our societies, unless there is a component addressing values.

That does not mean Western governments will not sometimes have to grit their teeth and accept unpleasant realities, like those Turkey has imposed on Sweden to gain support for NATO membership. But it does mean the surest guide to Western policy is to bet that when sacrifices are needed from free peoples, values are what motivates their voluntary action. The free world has the means to protect and advance its interests. Its challenge is how to use the tools of free societies to advance our free societies in the face of repression and aggression by its adversaries. And, in the final analysis, that is what Joseph Ellis was arguing for when he advocated that America’s founding fathers be removed from their pedestals and for US policymakers to meet the demands of our own historical time with courage and creativity.