America desperately needs a coherent foreign policy. Will 2016 candidates ever share their vision?

The next president will face a series of tough foreign policy decisions. How should America manage challenges from fast-rising China and respond to changes in the heart of Europe? What to do about ISIS? Should America become more involved in Iraq? Or Syria? Or Ukraine? What about Iran? Should Washington pursue more blockbuster trade deals like the Trans-Pacific Partnership?

Then there are the more fundamental questions: What role should America play in the world? What role do Americans want it to play? Those answers should provide the foundation for all others.

Recent polling suggests Americans want Washington to play a more modest, less expensive international role. Should Washington begin to mind its own business, let other countries solve their own problems and focus instead on rebuilding America’s strength from within? Call this option “Independent America,” a nation that has declared its independence from the responsibility to intervene in other people’s problems.

Or should Washington pursue an ambitious foreign policy, but one designed solely to make America more secure and more prosperous, not to foist our values on others? Call this “Moneyball America,” a reference to the hyper-rational approach that Oakland A’s general manager Billy Beane used to win more baseball games at less cost.

Or maybe an increasingly volatile world demands leadership that only America can provide. Perhaps Americans and everyone else will be better off if democracy, freedom of speech, and individual liberty are universally respected. Who but America can lead the effort to promote, protect, and defend these values? Call this one “Indispensable America.”

There are distinctly different versions of America’s future, but each of them speaks to the assumptions and aspirations of a significant number of Americans. And at a moment when Washington badly needs a coherent foreign policy strategy, it should worry us that the two perceived presidential frontrunners, Republican Jeb Bush and Democrat Hillary Clinton, are sending confusing signals on how they would lead.

At a moment when Washington badly needs a coherent foreign policy strategy, it should worry us that the two perceived presidential frontrunners, Republican Jeb Bush and Democrat Hillary Clinton, are sending confusing signals on how they would lead.

These two are in many ways the biggest foreign policy question marks in the presidential field. Jeb Bush has never served in Washington and has virtually no foreign policy track record. His campaign is working to craft a message that will draw conservative votes and dollars without embroiling him in the kind of needless controversy that he recently provoked with a series of confusing comments on his brother’s decision to invade Iraq. This was not simply a gaffe. It was a missed opportunity to help the American people understand how he would decide whether to invade and occupy a foreign country.

“The world is slipping out of control,” warns Bush. “We have no reason to apologize for our leadership and our interest in serving the cause of global security, global peace, and human freedom.” Sounds like the “Indispensable America” approach. But is this just talk, the rhetorical equivalent of an American flag lapel pin, and an appeal for support from traditionally hawkish Republican primary voters? If not, don’t taxpayers have a right to know what this grand vision of American power will cost?

At a moment of limited public tolerance for costly commitments abroad and the emergence of new international players with the political and economic self-confidence to say no to US plans and demands, American voters need straight answers from their candidates.

In Europe this week, Bush denounced Vladimir Putin as a “bully.” He warned that Washington must be “resolute” and “deal [with Putin] from strength.” He later added that we shouldn’t push Russia “into the arms of China.” This is a candidate looking to hit all the right notes rather than to define a coherent policy.

Unlike Bush, Hillary Clinton has an extensive foreign policy record and a paper trail long enough to fill the Library of Congress. Yet, her clear path to the Democratic nomination leads her to say almost nothing substantive on how she would lead.

A look at her record as secretary of state suggests an affinity for the “Moneyball” approach. As President Obama’s chief diplomat, she helped direct the so-called pivot to Asia, a plan to shift US resources toward the world’s most economically dynamic and geopolitically important region in order to capitalize on its long-term commercial opportunities and to meet the challenges posed by China’s expansion.

“Economic statecraft,” which Clinton described as a bid “to account for both the economics of power and the power of economics,” and her support for the Trans-Pacific Partnership (TPP), a colossal trade deal, were essential parts of that vision.

Her (ill-fated) effort to “reset” relations with Russia and a refusal to waste time and political capital on a futile bid to broker an Israeli-Palestinian peace deal suggest foreign policy pragmatism.

But candidate Clinton has tempered her support for a nuclear deal with Iran by arguing it must be part of a “comprehensive strategy to check Iran’s regional ambitions” and to “reinforce American leadership in the Middle East.” That’s a much more expansive view of Washington’s role in that chaotic region and a step back from the pivot to Asia, since “leadership in the Middle East” is more than a full-time job.

While serving President Obama she called Syria’s President Assad a “reformer.”Later, her book “Hard Choices” criticized Obama for not backing rebels who might have toppled him.

As secretary of state, she called TPP “the gold standard in trade agreements.” Perhaps to prevent a challenge from her left for the Democratic nomination, she now withholds her full support for the deal and issues warnings on labor rights, environmental protections, and other issues important to trade skeptics. Does she support TPP? No one seems sure.

President Obama once described his foreign policy strategy as “don’t do stupid stuff.” Not long after, Clinton took exception. “Great nations need organizing principles, and ‘Don’t do stupid stuff’ is not an organizing principle,” she told a reporter. Well said. Let’s hope she follows her own advice and moves beyond grandiose campaign rhetoric to share her vision with voters.

Foreign policy decisions affect the lives and livelihoods of millions of Americans. That’s why Jeb Bush, Hillary Clinton and all the presidential candidates must offer a clearly articulated strategic vision of America’s role in tomorrow’s world.

Ian Bremmer is the president and founder of Eurasia Group, the leading global political risk research and consulting firm. He has published nine books. His latest is "Superpower: Three Choices for America's Role in the World." He writes a weekly foreign affairs column for Time magazine, where he’s editor at large.