NEW YORK — No sooner had Mitt Romney and his newly picked running mate Paul Ryan of Wisconsin dubbed themselves “America’s Comeback Team” than President Barack Obama tweeted: “Romney-Ryan: The Go Back Team.”

Bring it on! Saving Private Romney is going to involve an ideological battle — over the size of government, the extent of Americans’ obligations to one another, even the soul of the country — that is no less than the United States deserves. An election should not be about candidates’ “likability” when a great nation is poised at the brink of decline. It should be a large debate, not a small one.

I had been observing the U.S. election from Europe, which knows about painful loss of power, and picked up principally a blur of slur. Now Romney has provided a spark. He has introduced a young man with conservative credentials that meet the Ayn Rand test and a whiff of the natural political animal.

Elections often hinge on simple ideas. Reagan asked Americans: Are you better off than you were four years ago? François Hollande defeated the incumbent in France by presenting himself as the “Monsieur Normal” who dislikes the rich. Romney, in picking Ryan, turned the election into a vote on a core question: Who can revive America?

(The rest of the world hardly comes into it for now: Ryan’s international credentials are nonexistent.)

The Romney gamble is huge because the line of Democrat attack against him and Ryan is so clear: They are the heartless would-be destroyers of Medicare, the health insurance program for retirees (who abound in battleground state Florida), and Medicaid; and they are the architects of a massive redistribution of income from bottom to top at a time when the top, unlike the middle and bottom, is doing just fine. They would offer the Bain blandishments to billionaires but bulldoze America’s social compact. (Contrary to a widespread European view, it exists).

The shape of the Republican counter-attack is equally apparent: Obama, with a little bit of studious this and a touch of worthy that, has no serious plan to stop Americans living on borrowed money. The economy is stalled, unemployment high. The country, to quote Clint Eastwood’s endorsement of Romney, “needs a boost.”
Behind this battleground a mountain stands. It is composed of debt. I applaud the Ryan pick because it places front and center what the chairman of the Joint Chiefs of Staff, Adm. Michael Mullen, has called the greatest long-term threat to America’s national security: its debt.

A country in ever greater hock to the Chinese, unable to invest in its schools, vulnerable to creditors pulling the plug, will not resist decline in the 21st century.

This election is about American revival, stupid.

President Obama has steadied America’s course, killed its greatest enemy and averted financial meltdown — but he has not lifted the United States from its sullen mood or undermining debt habits. Behind the now looming fiscal debate lies a values debate on how to galvanize America’s energies, as every great president has done. (A subtext of Romney’s choice is: I’m a risk-taker and can lead.)

The president has a deficit reduction plan. It would, among other things, cut military spending, preserve Medicare, and seek cost-saving health care efficiency. It makes a lot of sense. But try naming one big idea. Anxious nations need big ideas.

Ryan has built his reputation on having big ideas to balance America’s books. He is a genial guy; the geniality masks the fact that, as Norman Ornstein, the co-author of “It’s Even Worse Than It Looks,” a book on U.S. political dysfunction, put it: “His set of proposals are the most radical since Barry Goldwater.”

The poor, the needy, the old, college students seeking loans — all would be worse off under Ryan’s budget proposals, which would slash entitlements and turn Medicare into a voucher system. He wants a much simpler tax code: a 25 percent tax rate for higher incomes and 10 percent for lower incomes while closing the loopholes and eliminating deductions that see the very rich paying far less than 25 percent today.

Simplification would be good. There are countless ruses: Romney, my colleague James Stewart notes, has “been faulted for treating a horse partly owned by his wife as a loss-generating passive investment, rather than as a hobby.” (Don’t get me started on Romney’s treatment of animals.)

If the loopholes and deductions that left six of the richest Americans paying zero tax in 2009 — zilch! — are really closed, then there may indeed, as Stewart has argued, be some merit to Ryan’s tax proposal. Of course that’s a big if.
Romney will seek to fight the election on the values — freedom, opportunity, personal initiative, smaller government — that Ryan’s proposals seek to embody. Obama will counter with the specifics of lacerating entitlement cuts.

We may actually get a serious debate on the greatest long-term threat to U.S. national security. Romney, in choosing Ryan, has performed at least that service. The world is so interwoven that no single nation can be its guardian or guide. But an America of restored self-belief is essential to global well-being.