In a likely end to his public career, U.S. Secretary of Defense Leon Panetta is retiring after the Senate confirmed his successor, Chuck Hagel, on Tuesday.

Panetta’s previous experience at the Office of Management and Budget led some to hope that he would ably lead the Pentagon into a new world of limited resources. But he turned out to be a reincarnation of Ronald Reagan’s first defense secretary, Caspar Weinberger

Known as “Cap the Knife” from when he headed OMB, Weinberger turned into “Cap the Shovel,” promoting a large-scale military buildup even as deficits rose dramatically.

The most important issue facing the Pentagon today is how to operate with less money. The 9/11 terrorist attacks sparked a global campaign against al-Qaida and other terrorist groups, two lengthy wars, and several more limited operations. Military outlays exploded. The wars are winding down and al-Qaida is much weakened. But America’s aggressive, interventionist military policy is creating more enemies than it is killing and Washington’s fiscal position has collapsed. Even Panetta acknowledged that “We’re facing a huge budget crisis in the country.”

Yet rather than propose reasonable cuts, he engaged in scaremongering, proclaiming that we “cannot maintain a strong defense if sequester is allowed to happen.” Even though America would retain the world’s most advanced military and remain allied with every major industrialized state other than China and Russia.

Panetta also told Congress that the cuts would “undermine our ability to meet our national security objectives and require a significant revision to our defense strategy.” Yet such a revision is long overdue.

He worried that the cuts would reduce America’s “ability to be … engaged around the world” and “ability to support the Afghan war.” However, Washington should reduce its role after the collapse of hegemonic communism and rise of allied states, and the United States should withdraw from Afghanistan. Panetta has even opposed accelerating America’s exit from its long war in Afghanistan.

The shift from justified counter-terrorism to unjustified nation-building occurred long ago and failed to deliver honest and competent governance in Kabul. In response, Panetta gave the most cliched answer of all: “I think because of those that have paid the price for this war we owe it to them to stick to this mission and get it finished.” But that means more Americans will die for a tragic mistake.

Unfortunately, Panetta did not appear to learn any lessons from the debacle in Iraq. After the extended conflict following America’s unnecessary invasion, he lobbied to keep U.S. personnel stationed in Iraq.

Panetta’s final judgment on Iraq was striking. After Americans endured tens of thousands of casualties, triggered bloody strife within Iraq, and empowered Iran, he said: “I think all of us have to feel good about what’s happened.”

He also threatened Iran “if they proceed with a nuclear weapon.” He repeated the mantra “we’ll keep all options, including military action, on the table” at last year’s AIPAC conference. Yet he admitted: “Are they trying to develop a nuclear weapon? No. But we know that they’re trying to develop a nuclear capability. And that’s what concerns us.”

He never explained how such a weak state even with a few nuclear weapons could endanger America, and why Tehran could not be contained. He never contemplated the possibility that constantly threatening to unleash death and destruction on Iran might increase its interest in developing a nuclear deterrent.

Panetta also failed to press for major economies in military spending where they could be most easily achieved: Europe. EU members possess a combined economy and population greater than that of America and are capable of handling all conceivable threats, including from Russia.

Despite Washington’s fiscal straits, Panetta pressed to “rebalance toward the Asia-Pacific region” by enhancing the U.S. presence in Asia, adding ships and introducing U.S. Marines to Australia — enough to irritate but not enough to deter China. Ill-prepared U.S. allies, most notably Japan and the Philippines, are seeking U.S. military backing to enforce their disputed sovereignty over rocks of peripheral value.

Yet Washington’s defense guarantee has for years encouraged these nations to under-invest in their militaries. And the more the U.S. appears to threaten Beijing, the harder the latter will work to develop forces capable of deterring U.S. intervention in what China sees as its affairs.

Panetta has been no worse than the average defense secretary and is better than the worst of them — Robert McNamara and Rumsfeld on his second go-around, for instance. Panetta may have faced significant constraints from his boss, but there is no evidence that he tried to be a transformational chief. His failure to accommodate a rapidly changing world will be Panetta’s most important, and disappointing, legacy at the Pentagon.