Defense Secretary Ashton Carter, right, and Joint Chiefs Chairman Gen. Martin Dempsey arrive on Capitol Hill on May 6. (Manuel Balce Ceneta/AP)

Last week’s celebrations memorializing the end of World War II in Europe should remind us that in the 70 years since victory was declared, this country has been preparing for the next great war while actually fighting smaller ones.

The Dec. 7, 1941, surprise Japanese attack so embedded itself in the American psyche that avoiding another Pearl Harbor has repeatedly been a successful rallying cry for increased defense spending.

The nation quickly demobilized after Japan’s surrender in September 1945, but defense spending began to rise in the 1950s during the Korean War, went even higher during the 1960s and 1970s for the Vietnam War and climbed again in the 1980s to meet alleged threats during the Cold War. Remember all that talk of a Soviet nuclear first strike that led to billions being spent on nuclear weapons and missile defense systems?

The Sept. 11, 2001, attacks — terrorism’s Pearl Harbor — justified additional spending to pay for 14 years of fighting in Afghanistan and Iraq and against terrorists worldwide.

In short, the United States has been preparing for war or been at war for at least two generations.

There are threats out there.

Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said Wednesday at a hearing of the Senate Appropriations subcommittee on defense that the situation today is “the most uncertain security environment that I have experienced in 40 years.”

Note, however, that he said the threats were the “most uncertain,” not the most dangerous to this nation’s survival. There is no axis of Nazi Germany and Imperial Japan attempting to conquer the world or a nuclear-armed Soviet Union seeking to spread communism.

Dempsey talked of Russia’s threat to Europe, Iran and its nuclear program, North Korea, a rising China and non-state actors such as the Islamic State, al-Qaeda and aligned terrorist groups. These state and non-state actors, Dempsey said, “For the first time in my career, they are both manifesting themselves simultaneously.”

The Joint Chiefs chairman, making probably his last Capitol Hill appearance to testify on a defense budget, said, “We are at a point where our global aspirations are exceeding our available resources.”

He’s right — but that also depends on how you determine what’s needed to fulfill those aspirations.

A significant part of the current fiscal 2015 core defense budget of $490.2 billion goes to pay for deterring major threats and the big war — i.e., Russia and China. The overall U.S. defense budget is roughly twice the combined amounts those countries were reported spending in 2014 — China at $136 billion and Russia at $81 billion.

When it comes to deterring those countries, the United States is far ahead in major conventional and nuclear weapons, while all three countries are building more advanced ones.

Do we need them all?

For example, at Wednesday’s hearing, Sen. Dianne Feinstein (D-Calif.) said she favored spending $1.2 billion to develop a new long-range stealth bomber designed to penetrate an enemy’s airspace and deliver a nuclear weapon. But she questioned spending $1.8 billion for a new air-launched, nuclear-capable cruise missile for that bomber that could be launched a thousand or more miles from the target.

Feinstein pointed out the missile was only half the true cost. Another $1.8 billion would be needed to pay for the Energy Department to extend the life of the W-80 nuclear warhead needed for the new missile.

“I question why we need this cruise missile that can deliver nuclear warheads from great distances in addition to the numerous gravity bombs, submarine-launch ballistic missiles and intercontinental ballistic missiles we’ve armed ourselves with,” Feinstein said.

Dempsey responded that “air defenses are improving around the world and that keeping that capability to penetrate air defenses with our nuclear deterrent is an important one.”

Then there are the additional billions the United States spends through the Pentagon’s Overseas Contingency Operations (OCO) account, which pays for fighting in Iraq, Afghanistan, Syria and elsewhere against terrorists. It’s an added $64 billion this year and could go higher next year, depending on Congress.

Congress has transferred some core Pentagon spending to the OCO account, since the latter doesn’t count against budget caps.

The recently passed, Republican-driven fiscal 2016 budget resolution includes a whopping $96 billion in the OCO account, $38 billion above the amount requested by President Obama.

Defense Secretary Ashton B. Carter last week called that approach “a road to nowhere” since OCO funds are meant to meet “temporary costs” and the core defense items need multi-year budgeting stability.

Carter and Dempsey also cautioned senators about the idea of setting up a humanitarian no-fly zone in Syria. It would end up being a major military operation, they said, and very costly.

“We would need to fight to create such a space and then fight to keep such a space,” Carter said, describing it as “a major combat mission.”

Dempsey noted the irony “about talking about doing more in the world” when the Pentagon was already facing a tight budget and the threat of further sequestration cuts.

For previous Fine Print columns, go to washingtonpost.com/fedpage.