Editor's note: Republican John Thune is the junior U.S. senator from South Dakota.
(CNN) -- Much of the country has been watching the debate in Washington over how our government spends money, and how much it spends.
The public attention is warranted: This important debate will help determine the future direction of our country. We will either move to the fiscally responsible path of living within our means, or continue down the dead-end road of reckless borrowing and spending.
President Barack Obama has been clear about which direction he prefers. In his latest budget, which he submitted to Congress a few months ago, he proposed more than $1 trillion in new deficit spending for next year alone and would have nearly doubled our debt in 10 years. The president's budget was rejected by the Senate 97-0.
Our nation has a debt of more than $14 trillion -- 95 percent of our gross domestic product. To put that in perspective, at the beginning of this year Greece was at 143 percent. That is what happens if we do nothing. But there is another option.
We could pass an amendment to the Constitution that would require our government to balance its budget and prevent it from spending more money than it collects. Senate Republicans have proposed such an amendment, and we hope to get a vote on it soon.
Forty-nine states have some type of balanced-budget requirement, including my home state of South Dakota. It is never easy, but these states do at least have to come up with a budget every year.
Of course, not every balanced budget is a good one. To make sure Washington does not fall back on the old trick of simply raising taxes to achieve balance, our amendment would cap spending at 18 percent of gross domestic product, compared with the 24 percent we are spending now.
That cap is not just plucked from thin air; 18 percent is our average level of tax revenues over the past 40 years. Under current tax policy, that is where they are expected to be again in just a few years. At that level, limiting government spending to 18 percent of GDP would balance the budget without raising anyone's taxes.
The nonprofit Tax Foundation reported in 2010 that more than a third of new tax revenue would come from business income if high-income personal tax cuts expire, which the Democrats want. But allowing taxes to rise for these job creators will not improve our struggling economy, it will only hurt it more. With unemployment more than 9 percent, we should be doing all we can to make it easier, not harder, for businesses to hire and grow.
Continuing to rack up more and more debt will not help our economy either. Economists estimate that our debt is already costing us a million jobs in addition to the $213 billion in interest payments this year alone.
Twenty-nine years ago this week, President Ronald Reagan led a rally of thousands of people on the Capitol steps calling for a balanced-budget amendment, saying, " 'Crisis' is a much abused word today, but can we deny that we face a crisis?"
The federal debt then was $1 trillion. If that was a crisis, what do we face today with a debt more than 14 times as high?
Whatever you call it, clearly we need to get serious about finding a solution. There are already laws on the books that try to get our government to spend responsibly, but Congress routinely ignores them. Democrats in the Senate have ignored for more than 800 days the law requiring them to pass a budget of any kind.
The only real solution is a constitutional amendment that will require Congress to balance the budget. The choice we face is simple. We can balance our budget, or we can watch our country go bust.
The opinions expressed in this commentary are solely those of John Thune.