"National security" is a highfalutin phrase for a problem that can be stated quite simply: We have enemies. What do we do about them? Since this is a matter of life and death, it's worth asking: What national security policies can we expect the next commander in chief to implement?
Let's acknowledge that we can only make educated guesses. Presidential candidates have been known to say what they think voters want to hear and then, after winning election, go off in an entirely different direction.
Beyond that, circumstances change. President George W. Bush did not come into office expecting to spend most of his energy fighting terrorists and their sponsors. President Obama's experience recalls a quip often attributed to the communist revolutionary Leon Trotsky: "You may not be interested in war, but war is interested in you.
The websites of the two leading candidates are only minimally informative. The Hillaryclinton.com site features a national security page that is long on goals — e.g., "keep America safe and secure," "defeat ISIS," "strengthen our alliances" — but short on specifics about how those goals would be achieved.
The site goes on to tell us that, as secretary of state, "Hillary worked to restore America's leadership in the world." How that worked out, it doesn't say. It credits her for "building a global coalition to impose crippling sanctions against Iran." Actually, the administration in which she served was unenthusiastic about the sanctions project and ended it prematurely. Readers also are informed that Mrs. Clinton "supported President Obama's decision to bring Osama bin Laden to justice." Glad that's been cleared up.
As for Donald Trump: Aside from marrying two fashion models born in Eastern Europe, his experience in foreign affairs has been limited. To many of his supporters, that's a plus: In their judgment, the "experts" have been doing a lousy job.
The Donaldjtrump.com site lists seven "positions," three of which touch on foreign policy — "Pay for the wall," "U.S.-China trade reform" and "immigration reform" — but there's really nothing on national security.
A month ago, however, Mr. Trump delivered his first national security and foreign policy speech (a speech that, I suspect, a few foreign policy "experts" helped draft). While I wouldn't rank it up there with the Gettysburg Address, it was by no means incoherent.
It also was within the broad parameters of conservative thinking. Mr. Trump claimed he would "spend what we need to rebuild our military. Our military dominance must be unquestioned."
He pledged that Iran's rulers "will never, ever be allowed to have" nuclear weapons. He called Israel "our great friend" and "a force for justice and peace." He was sharply critical of Mr. Obama's rapprochement with Cuba and his failure to deal forcefully with China and North Korea.
Mr. Trump believes attempts to export democracy are fool's errands. He thinks the trade deals of recent years — including the North American Free Trade Agreement — were to America's disadvantage. He says he would cut better deals. Does he also incline toward protectionism rather than free trade? Quite possibly.
On some sensitive issues, he was more nuanced — or less reckless — than in the past. For example, he emphasized that "we're going to be working very closely with our allies in the Muslim world, all of which are at risk from radical Islamic violence, attacks and everything else."
He added: "We need a long-term plan to halt the spread and reach of radical Islam." He hasn't come up with one yet but said he would — indeed he vows to come up with whatever plans, policies and strategies are necessary to "make America great again."
Is he narcissistic? Is he nurturing a cult of personality? Of course, but that's been his secret sauce from the start. Anyone who doesn't get that is not paying close attention. Anyone who doesn't perceive the danger in that is ignoring history.
Back to Mrs. Clinton: Unlike Mr. Trump, we know not just what she's said but also what she's done. She voted for the intervention in Iraq and then, when the effort faltered, did a quick volteface, even opposing the "surge" at a time when evidence of its success was abundant.
She mistakenly believed she could "reset" relations with Vladimir Putin (as Mr. Trump does now, apparently). She pushed for toppling Libyan dictator Moammar Gadhafi but, despite the Iraq experience, didn't plan for the day after.
Despite all that, she is seen by many analysts, including more than a few on the right, as more muscular on national security than most Democrats — a "liberal internationalist," meaning she doesn't believe, as many on the left do, that American power is a problem rather than a solution. And we can assume she understands the convoluted processes of foreign policy — how the White House, State Department, Defense Department, Congress and the intelligence agencies interrelate and interact. Whether she's mastered those processes is a separate question.
Mr. Trump has proved a quick study when it comes to politics. He broke what almost everyone thought were the hard-and-fast rules of a primary campaign and beat a long list of more experienced opponents. Can he do the same when it comes to policy? Maybe. Maybe not.
In the final analysis, both candidates are like a box of chocolates: We don't know what we're gonna get. Heartburn, obesity and worse cannot be ruled out.
What I hope both candidates understand: America has enemies. They are serious, ruthless and lethal. They will test the next president — probably sooner rather than later.
Which candidate is better equipped to deal with this threat? You and I and others who view national security as a vital issue have a little more than five months to figure that out.