WASHINGTON — The three men President Barack Obama has nominated to foreign and national security policy posts in his second term share a demonstrated independent streak — each has challenged his own institution or party in wartime — but analysts say that doesn’t necessarily portend any big changes to U.S. diplomacy or defense strategy.

Indeed, while Obama portrayed his nominees — Sen. John Kerry to head the State Department, former Sen. Chuck Hagel to lead the Department of Defense, and counterterrorism adviser John Brennan to direct the Central Intelligence Agency — as patriotic trailblazers, some analysts doubt whether the trio will bring any real shakeups to U.S. policy.

“My sense is that, in spite of all the hand-wringing — especially surrounding Hagel — there’s less here than meets the eye,” said Toby C. Jones, director of the Center for Middle Eastern Studies at Rutgers University in New Jersey. “Obama and the administration have often staked the claim of foreign policy innovation and independence, but I think they have more in common with their predecessors than not.”

Both the nominations that Obama announced Monday — Brennan to head the CIA and Hagel to lead the Pentagon — promise at least some controversy as they seek required Senate approval.

Brennan is an Arabic-speaking career spy who’s been a staunch defender, or even “godfather,” of Obama’s controversial drone program. Critics from the left also question his service during the Bush administration era of torture and extraordinary rendition for terror suspects, while a few right-wing detractors have seized on out-of-context quotations to paint him as soft on Islamist extremists.

Hagel, who represented Nebraska for two terms in the U.S. Senate, is a onetime Republican star who’s drawn criticism for publicly questioning the United States’ unconditional support for Israel, calling for direct talks with Iran and the radical Palestinian group Hamas, and speaking out against the “surge” tactic in Afghanistan. Hagel angered his fellow Republicans by being one of three GOP senators who broke ranks in 2006 to demand an early withdrawal of U.S. forces from Iraq.

Kerry, the current senior senator from Massachusetts and 2004 Democratic presidential nominee whose nomination to succeed Hillary Clinton was announced last month, is the least controversial, and his nomination is expected to sail through.

While the president is expected to husband most of his time and energy for battles over domestic policy on Capitol Hill, his national security team would be charged with confronting a raft of pressing international issues. They include keeping the U.S. out of a conflict over Iran’s nuclear program that could upend the global economy, containing spillover from Syria’s civil war, plotting a smooth Afghanistan troop pullout and avoiding tensions with China over the so-called “pivot” to Asia.

But international crises often interfere with a president’s best-laid plans.

“The administration, left to its own devices, would like to do exactly that,” Richard Armitage, George W. Bush’s deputy secretary of state, said of Obama’s goal to concentrate on domestic economic policy. “But you don’t have that luxury. A terrorist attack or a kidnapping of Americans can put you in a whole different game.”

As for Obama’s decision to redirect U.S. national security policy away from Europe and toward Asia, Armitage said that it could be difficult for Hagel to beef up U.S. military commitments to Asian allies at a time when he would be looking to slash Pentagon spending as part of Obama’s budget-cutting efforts.

Kerry, meanwhile, would be running a State Department that long has been hampered by insufficient resources and was blasted by an independent panel’s recent findings of deep-rooted managerial problems that contributed to the bungled response to deadly Sept. 11 attacks on U.S. posts in Libya.

Syria could be another snag in the planned pivot toward Asia. The conflict is approaching the two-year mark, with tens of thousands of casualties and millions displaced, and an Obama administration that rejects imposing a no-fly zone and providing lethal assistance to the rebels.

If the bloodshed continues or seeps across Syria’s borders, however, Obama’s new security team might be forced to re-evaluate the current U.S. positions, especially when it comes to arming the rebels, whose best fighters are Islamists with an al-Qaida-style agenda for a post-Assad Syria. So far, the nominees have shown reluctance to become embroiled in Syria.

Kerry, a strong proponent of the NATO-led intervention in Libya, questioned in a hearing last summer whether a no-fly zone in Syria was “either practical or advisable.” Hagel insisted on working through the United Nations and the Arab League to find a solution because “the last thing you want is an American-led or Western-led invasion into Syria,” he told Foreign Policy magazine in May.

Brennan, speaking to a Washington forum in August, said that direct U.S. involvement “might increase the bloodshed,” but he added that Obama had tasked counterterrorism officials with examining scenarios that would give the rebels the upper hand against President Bashar Assad’s mostly intact military.

Brennan’s nomination, analysts said, was Obama signaling his approval of the accelerated drone program.