US Secretary of Defense Chuck Hagel submitted his resignation Monday and President Obama accepted it in a brief ceremony in the White House Rose Garden. Obama praised Hagel so lavishly that one might think he was in line for a promotion rather than abrupt dismissal from his government post.

The US media is full of speculation as to the reasons for Hagel’s ouster, as well as the identity of his likely successor. While a clear account has yet to emerge, there seems little doubt that he was sacked because the White House wanted a more aggressive pursuit of its military goals, particularly in the Middle East.

Last month, Hagel reportedly wrote an irate memorandum to the White House criticizing what he regarded as the failure of the National Security Council, under National Security Adviser Susan Rice, to spell out a coherent policy in relation to the US military intervention in Iraq and Syria. He apparently had some differences, as yet not made public, with administration policy in Ukraine as well.

Some reports suggest that Hagel was resisting White House efforts to target the Assad regime in Syria, feeling that this could cut across the US military effort against the Islamic State in Iraq and Syria (ISIS), which is fighting both the US-backed government in Baghdad and the Russian- and Iranian-backed regime in Damascus. He also backed the demands of military commanders in the region for greater flexibility in using their forces.

But there are myriad other points of conflict within the military-intelligence apparatus over the US buildup in the Asia-Pacific region, the ongoing confrontation with Russia in Ukraine and eastern Europe, and the management of multiple conflicts in the Middle East—Iran, Iraq, Syria, Yemen, Egypt and Libya, to name only the most explosive.

There are some indications that Hagel had lost what little support he once had among the top military brass, at least in part because he was not as effective a bureaucratic infighter on Pentagon budget issues as his two immediate predecessors, Robert Gates and Leon Panetta. Even the gargantuan resources regularly made available to the US military have been strained by the unprecedented scope of US overseas operations--from the Pacific to Central Asia, and from the Middle East and West Africa to Europe.

In recent months, General Martin Dempsey, chairman of the Joint Chiefs of Staff and the highest-ranking military officer, effectively shouldered Hagel aside at press briefings and other public venues and was said to have the backing of the White House for a more aggressive posture in the war against ISIS.

The sacking of Hagel follows by two days the official White House leak of plans to considerably expand US military activity in Afghanistan in 2015 and 2016, reversing Obama’s pledge that combat operations there would end December 31. Two weeks before, Obama announced he was doubling US troop strength in Iraq as part of the campaign against ISIS.

Hagel, a former Republican senator from Nebraska and Vietnam War enlisted man, was hardly a “dove,” but he evidently had reservations about the efficacy of more aggressive deployment of US military forces, particularly ground troops.

USA Today headlined a column on his dismissal: “Hagel Exit Signals a Return to War Footing,” citing the escalation in both Iraq and Afghanistan. NBC News had a similar report, quoting a “source close to Hagel and top Pentagon officials” to the effect that “Rather than winding down two wars, we’re winding up.”

The dismissal of a defense secretary is not a minor matter. This is one of the most critical positions in the capitalist state, standing sixth in the line of succession to the presidency (after the vice president, speaker of the House of Representatives, president pro-tem of the Senate, secretary of state and secretary of the treasury). The defense secretary heads one of the largest organizations on the planet, with more than two million uniformed and civilian personnel and another million contractors, and greater resources than the military forces of the next 15 countries combined.

There are three previous cases, since the Department of Defense was established in 1947, where a defense secretary was sacked in the sixth or seventh year of a two-term presidency, and in each instance it was an indication of severe crisis for American imperialism.

In late 1967, Robert McNamara submitted his resignation to President Lyndon Johnson as the US position in Vietnam crumbled. He left office just as the Tet offensive in February 1968 signaled the eventual American defeat in the war.

In late 1987, Caspar Weinberger submitted his resignation to President Ronald Reagan under the shadow of his impending indictment for authorizing illegal weapons shipments to Iran, part of the Iran-Contra scandal.

In late 2006, Donald Rumsfeld was forced out by President George W. Bush in the midst of the deteriorating US position in Iraq and after the Republican Party lost control of both the House and Senate in midterm elections.

Now, eight years later, Hagel has been fired after the Democratic rout in this month’s midterm elections and the decision to escalate US military operations in Afghanistan, Iraq and Syria, and amidst ongoing confrontations with Russia over Ukraine and with China in the Asia-Pacific.

It is too soon to identify exactly which issues proved to be decisive in Hagel’s ouster. This is in part because there was no public discussion of the policy differences within the administration or between the White House and the Pentagon.

American politics has acquired an ever more byzantine character, where life-and-death decisions are made behind closed doors through methods of intrigue and provocation, calculated leaks and deliberate misinformation. The American people are entirely excluded from this process.

During the months leading up to the November 4 vote, Obama was engaged in a series of high-level discussions to shift towards a far more aggressive foreign policy, but not a hint of this was revealed to the voters before they cast ballots. According to reports, he was holding discussions with Hagel in October that eventually led to the latter’s dismissal.

The American people will have just as little say over the changes in US military and foreign policy that will be ushered in through the selection of Hagel’s successor. Media speculation immediately focused on Michele Flournoy, who held the number three position in the Pentagon under Gates and Panetta.

While the press focused on Flournoy becoming the first woman Pentagon chief, the real significance of her selection would be a turn to aggressive counterinsurgency policies in both Afghanistan and Iraq-Syria. She is a co-founder of the Center for a New American Security and was a leading Democratic backer of the 2007 Bush surge of troops into Iraq. Once in office under Obama, she advocated similar policies in Afghanistan in 2009-2010, when the administration tripled the number of US troops deployed in that war.

According a report in the Guardian, Flournoy would be the generals’ choice to succeed Hagel. She “still enjoys a substantial base of support among senior generals and admirals across the services, something Hagel never enjoyed and Panetta had to build,” the newspaper wrote. “Her appointment to defense secretary would immediately be seen as an indication that a revised US approach against the Islamic State (ISIS) was in the offing, likely featuring the erosion of existing restrictions on US combat.”