By NICHOLAS D. KRISTOF — The New York Times.

President Obama in his speech on Wednesday confronted a topic that is harder to address seriously in public than sex or flatulence: America needs higher taxes.

That ugly truth looms over today’s budget battles, but politicians have mostly preferred to run from reality. Mr. Obama’s speech was excellent not only for its content but also because he didn’t insult our intelligence.

There is no single reason for today’s budget mess, but it’s worth remembering that the last time our budget was in the black was in the Clinton administration. That’s a broad hint that one sensible way to overcome our difficulties would be to revert to tax rates more or less as they were under President Clinton. That single step would solve three-quarters of the deficit for the next five years or so.

Paradoxically, nothing makes the need for a tax increase more clear than the Republican budget proposal crafted by Representative Paul Ryan. The Republicans propose slashing spending far more than the public would probably accept — even dismantling Medicare — and rely on economic assumptions that are not merely rosy, but preposterous.

Yet even so, the Republican plan shows continuing budget deficits until the 2030s. In short, we can’t plausibly slash our way back to solid fiscal ground. We need more revenue.

Kudos to Mr. Obama for boldly stating that truth in his speech — even if he did focus only on taxes for the very wealthiest. I also thought he was right to say that we need spending cuts — including in our defense budget. Mr. Obama didn’t say so, but the United States accounts for almost as much military spending as the entire rest of the world put together.

As I see it, there are three fallacies common in today’s budget discussions:

• Republicans are the party of responsible financial stewardship, struggling to put America on a sound footing.

.
In truth, both parties have been wildly irresponsible, but in cycles. Democrats were more irresponsible in the 1960s, the two parties both seemed care-free in the ’70s and ’80s, and since then the Republicans have been staggeringly reckless.

After the Clinton administration began paying down America’s debt, Republicans passed the Bush tax cuts, waded into a trillion-dollar war in Iraq, and approved an unfunded prescription medicine benefit — all by borrowing from China. Then-Vice President Dick Cheney scoffed that “deficits don’t matter.”

This borrow-and-spend Republican history makes it galling when Republicans now assert that deficits are the only thing that matter — and call for drastic spending cuts, two-thirds of which would harm low-income and moderate-income Americans, according to the Center on Budget and Policy Priorities. To pay for tax cuts heaped largely on the wealthiest Americans, Republicans in effect would gut Medicare and slash jobs programs, family planning and college scholarships. Instead of spreading opportunity, federal policy would cap it.

• Low tax rates are essential to create incentives for economic growth: a tax increase would stifle the economy.

.
It’s true that, in general, higher taxes tend to reduce incentives. But this seems a weak effect, often overwhelmed by other factors.

Were Americans really lazier in the 1950s, when marginal tax rates peaked at more than 90 percent? Are people in high-tax states like Massachusetts more lackadaisical than folks in a state like Florida that has no personal income tax at all?

Tax increases can also send a message of prudence that stimulates economic growth. The Clinton tax increase of 1993 was followed by a golden period of high growth, while the Bush tax cuts were followed by an anemic economy.

• We can’t afford Medicare.

.
It’s true that America faces a basic problem with rapidly rising health care costs. But the Republican plan does nothing serious to address health care spending, other than stop paying bills. Indeed, Medicare is cheaper to administer than private health insurance (2 percent to 6 percent administrative costs, depending on who does the math, compared with about 12 percent for private plans). So the Republican plan might add to health care spending rather than curb it.

The real challenge is to control health care inflation. Nobody is certain how to do that, but the Obama health care law is testing some plausible ideas. These include rigorous research on which procedures work and which don’t. Why pay for surgery on enlarged prostates if certain kinds of patients turn out to be better with no treatment at all?

Ever since Walter Mondale publicly committed hara-kiri in 1984 by telling voters that he would raise their taxes, politicians have run from fiscal reality. As baby boomers age and require Social Security and Medicare, escapism will no longer suffice. We need to have a frank national discussion of painful steps ahead, and since I’m not a politician, let me be perfectly clear: raise my taxes!