President Barack Obama aptly began his second inaugural speech by invoking the opening lines of our nation’s opening document. As he explained:

“What makes us exceptional — what makes us American — is our allegiance to an idea, articulated in a declaration made more than two centuries ago:

“ ‘We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights, that among these are Life, Liberty, and the pursuit of Happiness.’ ”

A few minutes later, the president fairly pointed out:

“But we have always understood that when times change, so must we; that fidelity to our founding principles requires new responses to new challenges; that preserving our individual freedoms ultimately requires collective action.”

Near the end of the speech, he blended his theme of America’s lofty ideals with this practical reminder:

“Being true to our founding documents does not require us to agree on every contour of life; it does not mean we will all define liberty in exactly the same way, or follow the same precise path to happiness. Progress does not compel us to settle centuries-long debates about the role of government for all time — but it does require us to act in our time.”

Therein, of course, lies the test of this — or any other — time: What decisions are required of our leadership as “the centuries-long debates about the role of government” continues.

More specifically for our time: When — and how — is the U.S. government going to get its fiscal act together?

The president did mention some other issues Monday, including climate change, foreign policy, pay equity, gay rights and the need to strengthen the middle class.

But this line seemed a worthy acknowledgement of what should be the overriding issue — America’s endangered bottom line: “We must make the hard choices to reduce the cost of health care and the size of our deficit.”

Unfortunately, the president also said: “The commitments we make to each other — through Medicare, and Medicaid, and Social Security — these things do not sap our initiative; they strengthen us.”

Actually, those demographically threatened entitlement programs are being progressively weakened — as is our nation — by our persisting failure to fundamentally overhaul them. The president and his party have repeatedly resisted the “hard choices” needed for that task — despite his own bipartisan debt commission’s recommendation that those overdue decisions must be made.

Instead, President Obama pushed what amounts to a huge new entitlement program — the misnamed Patient Protection and Affordable Care Act — through Congress in 2010 without a single Republican vote.

Yes, Mr. Obama inherited an economy in freefall four years ago, largely due to the 2008 mortgage-industry meltdown. But he has now presided over four straight trillion-dollar-plus deficits — and has rejected GOP initiatives for significant spending reductions and entitlement reform.

Indeed, he scored another political victory in the year-ending “fiscal cliff” drama by postponing spending cuts beyond any reasonable expectation that they will ever he carried out. He has now apparently scored another triumph for unrestrained spending on the debt-ceiling deadline that looms at the end of next month, with GOP House leaders backing off from their threat to not raise the limit without major budget cuts.

This is the same president who said, in his 2008 inaugural speech: “Our time of standing pat, of protecting narrow interests and putting off unpleasant decisions — that time has surely passed.”

Maybe Mr. Obama, knowing he doesn’t have to run again, will finally make some of those “unpleasant decisions.” After all, Monday’s speech did include this timely history lesson about Americans’ traditional awareness of Washington’s limits:

“Through it all, we have never relinquished our skepticism of central authority, nor have we succumbed to the fiction that all society’s ills can be cured through government alone. Our celebration of initiative and enterprise; our insistence on hard work and personal responsibility, are constants in our character.”

And during his closing, the president presented this challenge: “Decisions are upon us, and we cannot afford delay. We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate. We must act, knowing that our work will be imperfect.”

Meanwhile, all Americans must hope that in President Obama’s final term, he and other elected officials from both parties will be more willing to make the “hard choices” required to restore our nation’s fiscal viability.

Otherwise, our ongoing “pursuit of happiness” is going to become an increasingly difficult chase.