In a recent op ed, former Senators Joseph Lieberman and Jon Kyl darkly warned of the dangers of “isolationism.” They never actually define what isolationism is, nor who supposedly believes in it, aside from a link to a single speech delivered earlier this year by Sen. Rand Paul, R‑Ky., at the Heritage Foundation. The article raises a host of questions, and answers none. Here are just a few:

Are those people who believe that the primary object of the U.S. military is to defend the United States and its vital interests isolationists? Is it “isolationist” to believe that a government’s most sacred obligation is to defend its people from harm, and therefore that other countries should take responsibility for their own security?

When people point out that many of our Cold War‐​era alliances amount to a particularly generous form of foreign aid, with Americans paying to defend other countries that could defend themselves, is that isolationism? Many of these free riders — most recently France — have chosen instead to plow money into bloated welfare states, generous old age pensions, and subsidized transportation, housing and health care. Is it isolationist to observe that such an arrangement imposes unfair burdens on the Americans who pay the bills?

Or what about other forms of foreign aid? Are the people who question the wisdom of sending tens of billions of dollars to foreign governments isolationists? The late economist Peter Bauer characterized foreign aid as “a process by which poor people in rich countries help rich people in poor countries.” Others have shown that a few trillion dollars spent over the course of five decades has had little, if any, impact on stimulating long‐​term economic growth, and more likely retards it. Do Lieberman and Kyl disagree?

How would Lieberman and Kyl describe those Americans who oppose U.S. military intervention in Syria? A recent Rasmussen Poll finds that just 17 percent of Americans want the U.S. to become more involved, while 50 percent want us to leave the situation alone. A New York Times/​CBS News Poll found that 24 percent of Americans believed that the United States had a responsibility to act, but 62 percent said that it does not. When people observe that this country has an uneven track record at picking winners and losers in bloody civil wars in distant lands, are they being isolationists?

The curious alliance of Lieberman and Kyl itself raises a host of questions. They appear to agree that the Americans should spend much more on the military than we do today, more on average than we spent during some of the darkest days of the Cold War. But how will we pay for it? It would be logical to speculate that Joseph Lieberman, the Democratic Party’s vice presidential nominee in 2000 who earned a rating of 5 out of 100 from Americans for Tax Reform, believes that we should raise taxes.

But does Jon Kyl? He signed the Taxpayer Protection Pledge and earned a perfect 100 from Americans for Tax Reform on taxes and spending. If tax increases are off the table, what other government spending cuts would Kyl endorse in order to fund a still larger military? Or would both men prefer to avoid these hard questions and simply pile an additional layer of debt for our children and grandchildren to pay? They don’t say.

This much is clear: If we continue on our current path, with other countries growing more and more dependent on U.S. military power and less inclined to develop their own, the burdens on American taxpayers and U.S. troops will only grow heavier. The better solution is to encourage other countries to take responsibility and pay at least some of the costs, consistent with the benefits that they derive from a peaceful and prosperous world.

Lieberman and Kyl are welcome to affix a label to that approach, but most Americans would characterize it as basic fairness and common sense.

For the most part, the American people want to be engaged in the world without being in charge of it. And to the extent that some Americans might prefer to turn their backs on the world, the interventionists have no one to blame but themselves. The most vocal opponents of so‐​called isolationism today were the most vocal advocates of those wars in the past decade that have so soured the American public on foreign policy, generally, and foreign military entanglements, especially.