Former Sens. Jon  Kyl (R-Ariz.) and Joe Lieberman (I-Conn.), eyeing isolationists on the right and left, write:

Sen. Marco Rubio (R-Fla.) (Joe Raedle/Getty Images Sen. Marco Rubio (R-Fla.) (Photo: Joe Raedle/Getty Images)

In the poll that drove the headlines on April 30, 47 percent of respondents said they want their country to be “less active in world affairs.” Thirty percent favored the current level of activity, while 19 percent wanted the United States to be more active. No one said they wanted to “retreat from the world stage.”

But there’s more nuance here: Fully 55 percent of those polled agreed that “[w]e need a president who will present an image of strength that shows America’s willingness to confront our enemies and stand up for our principles.” Only 39 percent wanted a president who emphasized “a more open approach and is willing to negotiate with friends and foes alike.”

Similarly, in a much discussed major survey published last November, the Pew Research Center found that 51 percent of Americans thought the president’s approach to foreign policy was “not tough enough,” with only 37 percent saying his policies were “about right.”

After reviewing more polling they conclude:

The time has come for the advocates of U.S. passivity to stop talking about the popular mandate they never had and to speak honestly to the American people. And it’s high time for others to stop cowering before this imaginary consensus. There are real challenges to U.S. security and prosperity out there — from Ukraine to Iran, Syria to China. It’s time to give Americans the leadership they want.

I would argue that the polling looks worse than it might otherwise, both because Republicans are averse to giving this president any encouragement for half-hearted military efforts with no follow-through (Libya) and because the country at large hasn’t been presented with realistic and compelling arguments for internationalism. In the 1930s FDR began to made the case for intervention. In the 1980s Reagan made the case against the evil empire and gave Americans confidence we could prevail. “We win, they lose” is how he described his Cold War approach.

To his credit, Sen. Marco Rubio (R-Fla.) used the Republican weekly radio address to make the case for U.S. leadership. He explained succinctly,

In the face of all these challenges here at home, there are those who argue that we need to focus less on what is happening around the world. But this would be a terrible mistake. Because today our economic prosperity depends on our ability to sell products and services to other nations, to communicate openly and reliably and to travel freely. Millions of the best jobs we have today – and millions of the best jobs we will have in the future – will depend on international trade and commerce. Today, foreign policy is an important part of our domestic policy. And our economic well-being is deeply dependent on our national security.

As for Ukraine specifically, Rubio said:

Some ask, ‘Why is this our problem?’ Well, because we cannot allow the precedent to be set that in order to engage the West in trade and commerce, smaller nations must first seek the permission of their more powerful neighbors. President Obama talks tough about Vladimir Putin. But his actions have not gone far enough to change Putin’s calculation that the benefits of his aggression outweigh the costs.

And that’s why this week Senate Republicans introduced a bill that would increase sanctions. It would provide Ukraine with defensive military assistance. It would impose tough new sanctions on sectors of Putin’s economy and on President Putin and his cronies. It urges the President to speed up deployments of missile defense in Eastern Europe and ensure that U.S. forces deployed in Europe are positioned strategically. And it would allow Europe to free themselves from their dependence on Russian natural gas by selling them more American natural gas.

Yet even these minimal steps (and, God forbid, helping Ukraine to defend itself!) the president resists. He ends wars, you see. But when aggressors don’t stop, his admonition amounts to refusal to defend against aggression.

The isolationists have the slippery slope argument wrong. They imagine if we start giving arms to Syria rebels today, tomorrow we’ll have boots on the ground. Or if we share intelligence with Ukraine, we’ll start World War III. To the contrary, procrastination leads to more calamitous results. As we know from the Cold War, containment including military rebuilding deters aggression. It is when we let repression devolve into genocide and bullying into invasion that the Hobson’s choice between chaos or capitulation comes into play. (And Libya, of course, disproved the “light footprint” idea when the administration took its eye off the ball and did not respond to the infiltration of jihadis into Libya.)

Rubio and other GOP leaders need to make the case over and over again: If America doesn’t lead, we’ll have increased chaos and economic disruption. If America doesn’t act on the side of the oppressed, we’ll have more mass murders. “Act” doesn’t mean necessarily act militarily or act alone.

I would urge internationalists who aspire to the presidency to challenge the proponents of “Fortress America” to debate the issues of the day. Like the Panama Canal debate, it would begin an important conversation. Are we spending too much or too little on defense? Why has America lost influence in the Middle East? What’s the relationship between human rights and national security? These and other big issues loom; the question remains whether we have politicians big enough to address them.

Before the heat of a presidential campaign, why not begin to educate the public now? If we don’t conduct a sustained discussion and present the case for American leadership, Americans will be puzzled as to why we should care about places like Ukraine, Syria and Venezuela.