At a time of tight defense budgets, why does the Air Force plan to spend billions of extra dollars so that a president 10 or more years from now can have two options if he or she wants to use bombers to attack an enemy with nuclear weapons?

There has been an irrationality attached to nuclear weapons strategy ever since the United States used the first two atomic bombs to end World War II almost 70 years ago. This is just the latest example.

At last Wednesday’s House Armed Services strategic forces subcommittee meeting on the fiscal 2016 nuclear weapons budget, Air Force Maj. Gen. Garrett Harencak, assistant chief of staff for strategic deterrence, was asked why we need a nuclear-armed, long-range missile mounted on strike bombers if we also have a penetrating bomber and the B61 nuclear gravity bomb.

He replied that having both a standoff weapon and the direct attack method by dropping bombs “vastly, vastly complicates a potential enemy’s defenses and most importantly . . . gives options that we would perhaps someday wish we had if we don’t pursue this.”

Robert Scher, the assistant defense secretary for strategy, plans and capabilities, put it more directly: “We should not be in a position where the only option that we give the president to use the air leg of the triad [strategic bombers, land-based and sub-based missiles] is putting a piloted airplane over enemy airspace to drop a gravity bomb.”

Think about that.

That future president would have the option to employ the planned, manned or perhaps unmanned long-range strike bomber (LRSB) to drop B61-12 nuclear bombs, both of which are now in development.

The proposed cost of 80 to 100 new LRSBs, at about $550 million each, could exceed $55 billion, although not all of it would be for the nuclear mission. The cost of development and production of a new B61 bomb is estimated at $10 billion, although some money would be allocated to fighter bombers attached to NATO.

That president’s other option would be to send new strike bombers — or the stealthy B-2A or older B-52s — but have them stay about 1,500 to 3,000 miles away from the target and fire new long-range standoff weapons (LRSOs) armed with the new W80-4 nuclear warheads, also now in development.

Unofficial estimates put the cost of producing the LRSO missiles and W80 warheads at $10 billion to $20 billion over the next 20 years.

How many nuclear options does that future president really need to deter a nuclear attack or respond to one?

Needless to say, that future president would also have the option of using some or all of the more than 1,000 nuclear warheads already deployed on U.S. nuclear-armed intercontinental ballistic missiles (ICBMs) — either the 420 that are land-based missiles with one warhead or those on 10 or more strategic submarines, each of which is expected to carry 16 missiles with three to five warheads.

Of course, there is the old Cold War reason to build all these weapons — the Russians are doing the same thing. That’s how both countries got above 10,000 nuclear weapons apiece two decades ago.

Arms control treaties between Moscow and Washington brought those numbers down. But the move by both countries to modernize their nuclear-capable long-range cruise missiles and bombers actually lets them take advantage of a loophole in the 2010 New Strategic Arms Reduction Treaty.

While limiting each side to 1,550 nuclear warheads on deployed land-based and sub-based ICBMs, deployed strategic bombers under the treaty count as only one warhead even if they’re equipped to carry dozens of nuclear bombs or a dozen or more air-launched, long-range nuclear missiles.

The unaccounted for air-launched missiles and bombs could quickly increase the allowable 1,550 warheads by several hundred or more nuclear devices, but still not count toward that overall limit.

By the way, the Defense Department and the National Nuclear Security Administration also are working on a new multibillion-dollar strategic submarine and a new land-based ICBM, plus a single upgraded warhead for those systems. However, their estimated operational dates are much further out than 10 years, guaranteeing that nuclear weapons will be around through at least 2050 .

On April 5, 2009, in Prague, President Obama set a goal of “a world without nuclear weapons” and got great applause. But then Obama added, “I’m not naive. This goal will not be reached quickly — perhaps not in my lifetime.”

The Senate ratified the new arms treaty on Dec. 22, 2010, but to get Republican votes for the two-thirds majority needed, Obama had to promise to modernize the American nuclear weapons complex and the nuclear delivery systems.

The treaty may have been a step forward to Obama’s goal of a weapons-free world, but the price he paid has turned out to be two steps backward.

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