In an election year, it's all too easy for politicians to defer hard choices until after the polls have closed in November. House Budget Committee Chairman Paul Ryan (R., Wis.) has taken the more difficult road with his "Path to Prosperity" budget.

Mr. Ryan's plan has received much attention for tackling America's spiraling expenditures on entitlements and domestic discretionary spending. Less reported is the budget's partial restoration of national defense as the No. 1 priority of the federal government.

Even within the framework of a plan to reduce outlays by $6.2 trillion over the next decade, Mr. Ryan has found a way to replace $214 billion of the $487 billion in military spending reductions that are in Barack Obama's budget. And he has done so while avoiding the tax increases proposed by the president.

Conservatives recognize that they have to deal with fiscal reality and get the federal government's balance sheet in order. That is why Mr. Ryan's plan is so bold. It does not cut indiscriminately, focusing instead on the true drivers of our spending crisis and recognizing that tax increases would worsen our economic situation.

The Ryan plan also helps to reverse what Defense Secretary Leon Panetta has called the "catastrophic" process of sequestration—the year-after-year, automatic cuts agreed to in last summer's debt-limit deal between the president and the House leadership. These cuts will eviscerate the United States military if Congress does not quickly pass a law to undo them this year. Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, has made plain the consequences of sequestration: "We would no longer be a global power."

The contrast between the House Republican budget and that of our current commander-in-chief is striking. President Obama has been arguing that raising taxes is the only solution to sequestration that he will accept. In other words, he asks the nation to decide between higher taxes and a weaker defense. Mr. Ryan rejects either solution.

Instead, Mr. Ryan takes some important first steps toward facing up to the true drivers of the federal government's money woes: spending through "entitlement" programs. These now consume roughly 60% of the federal budget, up from 20% in 1970. In contrast, national defense, which comprised nearly 40% of the budget in the 1970s, costs less than 20% today, even with current war spending. Absent reform, entitlements will spiral upward and crowd out all other federal spending—not just on the military.

It's incorrect to regard entitlements as mandatory programs. They reflect political choices about what kind of country we want and how we will govern ourselves. If we fail to reform entitlements, we'll go on pretending we can afford a retirement with benefits we never earned, paid for by our children and grandchildren. We'll be choosing an ever-more socialized medical system. We will in effect choose to become a European-style—and unsustainable—welfare state.

We will also be choosing to lay aside the burdens and inconveniences of world leadership. Mr. Obama insists that he doesn't believe America is in decline. But his redistributionist policies at home and his preference for "leading from behind" abroad can only be regarded as making exactly that choice.

The Ryan budget is not perfect for some conservatives. Many would like to see American military spending restored more rapidly and an even more aggressive approach to tackling the entitlement problem. But Mr. Ryan's budget is a choice about our future, and this is a time to choose—not hide behind the sequestration process.

If we want a strong America in a dangerous world, and a freer and growing economy for our citizens, it's time to choose the direction that Mr. Ryan is charting.

Mr. Brooks is president of the American Enterprise Institute. Mr. Feulner is president of the Heritage Foundation. Mr. Kristol is a director of the Foreign Policy Initiative. Their three organizations compose the Defending Defense coalition.