Judging by the latest signs and portents, President Obama and congressional Republicans appear to be at an impasse over taxes and spending, and the country might indeed be headed over the “fiscal cliff.” Next year’s economic sluggishness and partisan recriminations could make today’s look like a picnic.

The two parties and their allied pundits blame each other; each side has its points. But while everyone’s pointing fingers, let me at least wave in the direction of the Federal Reserve and its chairman, Ben S. Bernanke. There’s a case to be made that Bernanke’s low­interest-rate policies are part of the problem, too.

How so? Doesn’t the Fed make monetary policy according to its legal mandate — to fight unemployment while maintaining price stability? Hasn’t Bernanke repeatedly and forcefully urged Congress to adopt a sustainable long-term fiscal strategy?

And if all that’s true, as it is, what could the politically independent central bank’s pursuit of its mission possibly have to do with Congress’s handling of its tax-and-spend business?

The answer is: nothing directly or intentionally, but everything indirectly and unintentionally.

With the U.S. economy still reeling from the Great Recession, the Fed has been trying to stimulate economic growth by holding down interest rates, and it has pledged to keep doing so through mid-2015. It does this in large part by buying up government debt. Partly as a result, the United States was able to issue $4 trillion in new debt from 2009 through 2011, while keeping net interest costs at or below 1.5 percent of gross domestic product.

It’s perfectly consistent with the Fed’s mandate. And it sounds like a great deal for the government, too. According to more than a few economists, pundits and politicians, Congress should seize the opportunity to borrow and spend on growth-enhancing investments such as infrastructure.

However, in a properly functioning economy, rising government borrowing costs can play a useful role: Specifically, they are the market’s way of warning government that its debts are unsustainable.

Muffle that signal, as the Fed’s policy is doing now, and politicians are less able to guess right about how much time they really have to fix fiscal policy and to feel less pressure to do so.

According to the 2012 annual report of the global “central bank for central banks,” the Bank for International Settlements (BIS), “near zero policy [interest] rates, combined with abundant and nearly unconditional liquidity support, weaken incentives for . . . fiscal authorities to to limit their borrowing requirements.”

In short, the Fed isn’t making it harder for Congress and the president to do their job. It’s making it easier for them not to do their job.

The Fed alone is not responsible for today’s low rates. To some extent, they reflect investors’ flight to safe government bonds due to the lack of high-yielding alternatives in the sluggish private markets. Also, the central banks of China and Japan are doing their part by holding $1.1 trillion of Treasury debt each to offset their cumulative trade surpluses with us.

Bernanke has specifically and firmly denied responsibility for the politicians’ fiscal dithering. In an Oct. 1 speech, he rejected the notion that the Fed should use monetary policy “to try to influence the political debate on the budget.”

“Suppose, notwithstanding our legal mandate, the Federal Reserve were to raise interest rates for the purpose of making it more expensive for government to borrow,” the chairman said. “Such an action would substantially increase the deficit” — both by raising borrowing costs and by weakening the economic growth upon which government depends for revenue.

Bernanke was correct. But he was also pummeling a straw man. No one is saying that he is enabling the fiscal impasse on purpose — at least I’m not. Nor is anyone suggesting that he should reverse course on interest rates for the express purpose of disciplining the politicians.

The real point, as the BIS put it, is that “central banks are being cornered into prolonging monetary stimulus as governments drag their feet and adjustment is delayed.”

Bernanke can’t raise rates without blowing up the economic recovery. The recovery, in turn, buys time for Congress and the White House to address fiscal issues under benign conditions. Yet without the spur of higher rates, politicians are more likely to waste that time — and, consequently, blow up the economic recovery.

It’s anyone’s guess how much longer this game can go on, before markets finally do deliver an interest rate shock so powerful that even the Fed can’t counteract it. But I am pretty sure that whenever that shock comes, it will be sooner than we’d like.