Washington (CNN) -- Drone strikes are a necessary evil, but one that must be used with more temperance as the United States' security situation evolves, President Barack Obama said Thursday.
America prefers to capture, interrogate and prosecute terrorists, but there are times when this isn't possible, Obama said in a speech at the National Defense University in Washington. Terrorists intentionally hide in hard-to-reach locales and putting boots on the ground is often out of the question, he said.
Thus, when the United States is faced with a threat from terrorists in a country where the government has only tenuous or no influence, drones strikes are the only option -- and they're legal because America "is at war with al Qaeda, the Taliban and their associated forces," Obama said.
He added, however, "To say a military tactic is legal, or even effective, is not to say it is wise or moral in every instance. For the same progress that gives us the technology to strike half a world away also demands the discipline to constrain that power -- or risk abusing it."
Increased oversight is important, but not easy, Obama said. While he has considered a special court or independent oversight board, those options are problematic, so he plans to talk with Congress to determine how best to handle the deployment of drones, he said.
The nation's image was a theme throughout the speech, as Obama emphasized some actions in recent years -- drone strikes and Guantanamo Bay key among them -- risk creating more threats. The nature of threats against the United States have changed since he took office -- they've become more localized -- and so, too, must efforts to combat them, he said.
"From our use of drones to the detention of terror suspects, the decisions that we are making now will define the type of nation and world that we leave to our children," he said.
Today, al Qaeda operatives in Pakistan and Afghanistan worry more about protecting their own skin than attacking America, he said, but the threat is more diffuse, extending into places such as Yemen, Iraq, Somalia and North Africa. And al Qaeda's ideology helped fuel attacks like the ones at the Boston Marathon and U.S. diplomatic compound in Benghazi.
Obama said the use of lethal force extends to U.S. citizens as well.
On Wednesday, his administration disclosed for the first time that four Americans had been killed in counterterrorist drone strikes overseas, including one person who was targeted by the United States.
"When a U.S. citizen goes abroad to wage war against America -- and is actively plotting to kill U.S. citizens; and when neither the United States, nor our partners are in a position to capture him before he carries out a plot -- his citizenship should no more serve as a shield than a sniper shooting down on an innocent crowd should be protected from a SWAT team," Obama said.
To stop terrorists from gaining a foothold, drones will be deployed, Obama said, but only when there is an imminent threat; no hope of capturing the targeted terrorist; "near certainty" that civilians won't be harmed; and "there are no other governments capable of effectively addressing the threat." Never will a strike be punitive, he said.
Those who die as collateral damage "will haunt us for as long as we live," the president said, but he emphasized that the targeted individuals aim to exact indiscriminate violence, "and the death toll from their acts of terrorism against Muslims dwarfs any estimate of civilian casualties from drone strikes."
It's not always feasible to send in Special Forces, as in the Osama bin Laden raid, to stamp out terrorism, and even if it were, the introduction of troops could mean more deaths on both sides, Obama said.
"The result would be more U.S. deaths, more Blackhawks down, more confrontations with local populations and an inevitable mission creep in support of such raids that could easily escalate into new wars," he said.
The American public is split on where and how drones should be used, according to a March poll by Gallup.
Although 65% of respondents said drones should be used against suspected terrorists abroad, only 41% said drones should be used against American citizens who are suspected terrorists in foreign countries.
Guantanamo to shut down?
Guantanamo Bay also threatens to create new enemies of the state and diminish the country's moral standing in the world, Obama said, revisiting a campaign promise he made before his first term.
"The original premise for opening Gitmo -- that detainees would not be able to challenge their detention -- was found unconstitutional five years ago," he said. "In the meantime, Gitmo has become a symbol around the world for an America that flouts the rule of law."
Because of what Gitmo represents, some allies are reluctant to cooperate on investigations with the United States if a suspect might land at the controversial detention center, Obama said.
That's not to mention the economic implications, the president said. The country spends $150 million annually to imprison 166 suspects, and the Defense Department estimates that keeping Gitmo open may cost another $200 million "at a time when we are cutting investments in education and research here at home," he said.
Explaining that no prisoner has ever escaped a supermax or military facility -- and noting U.S. courts have had no issue prosecuting terrorists, some more dangerous than those at Guantanamo -- Obama said he would push again to close the detention center and appoint State and Defense department envoys to make sure the detainees are transferred to other countries.
Seventy percent of respondents to a February 2012 ABC/Washington Post poll said they approve of keeping the facility open for suspected terrorists. Only 24% said it should be closed.
One of his initiatives aims to lift a moratorium on transferring prisoners to Yemen, long a volatile land but now ruled by a government regarded by the United States as a "willing and able partner." Yemenis make up a significant portion of Guantanamo inmates.
In a statement issued through its embassy in Washington, Yemen's government welcomed the U.S. decision and vowed to "work with the United States to take all necessary steps to ensure the safe return of its detainees and will continue working towards their gradual rehabilitation and integration back into society."
Obama said he will insist on judicial review from every Guantanamo detainee, and when it's appropriate, terrorists will be transferred stateside to stand trial in courts and "our military justice system."
"Given my administration's relentless pursuit of al Qaeda's leadership, there is no justification beyond politics for Congress to prevent us from closing a facility that should never have been opened," the president said.
There are 86 inmates at Guantanamo who have been cleared for transfer, 56 of them from Yemen.
While Obama worked to close Guantanamo early in his first term, Congress enacted significant restrictions on the transfer of detainees from the prison that made its closure impractical.
This year, the State Department reassigned the special envoy who had been tasked in 2009 with closing the facility and lowered the post's profile by assigning the job to the department's legal adviser's office.
The problem has been exacerbated by the fact more than half the facility's inmates engaging in various forms of hunger strike, more than 20 of them being force-fed.
New dangers have emerged
Obama made the case that the al Qaeda terror network in the Afghan and Pakistan region has been weakened but that new dangers have emerged as the U.S. winds down operations in Afghanistan after more than a decade of war triggered by the 9/11 attacks.
Threats that have emerged come from al Qaeda affiliates, localized extremist groups and homegrown terrorists, like the two men suspected of attacking the Boston Marathon last month.
The administration has been considering shifting control of lethal drone operations from the CIA to the military. One senior administration official said the "military is the appropriate agency to use force," not to rule out the range of options needed to deal with threats.
By law, the military is not able to act in the covert way the CIA can in this particular arena and must answer to Congress.
In his confirmation hearing for CIA director, John Brennan expressed a desire to move the agency away from paramilitary operations and back to traditional areas of espionage.
"The CIA should not be doing traditional military activities and operations," he said.
Obama rejected the idea of a global war on terror in favor of a more focused approach that will engage on specific networks of extremists who threaten the United States.
The administration plans to avoid operations that will cause civilian casualties and wants to work with partners in its operations.
Use of force will be part of a larger strategy to deal with instability and hostility. Obama discussed strategies for promoting democratic governance and economic development and fostering U.S. engagement around the world.
The president also raised the unpopular topic of foreign aid, presenting it not as charity but as a means of national security. It amounts to less than 1% of the national a budget but is integral to fighting terrorism, he said.
"For what we spent in a month in Iraq at the height of the war, we could be training security forces in Libya, maintaining peace agreements between Israel and its neighbors, feeding the hungry in Yemen, building schools in Pakistan, and creating reservoirs of goodwill that marginalize extremists," he said.
Republican: Obama speech 'a victory' for terrorists
Several Republicans panned Obama's speech.
Rep. Michael McCaul, chairman of the House Homeland Security Committee, criticized the idea of closing the Guantanamo Bay prison and said, "The president's policies signal a retreat from the threat of al Qaeda."
"The Obama administration's return to a pre-9/11 counterterrorism mindset puts American lives at risk," the Texas Republican said. "This war will continue whether the president acknowledges it or not."
Sen. Saxby Chambliss of Georgia said that announcing plans to close the facility "sends the message to ... detainees that if they harass the dedicated military personnel there enough, we will give in and send them home, even to Yemen."
"The president's speech today will be viewed by terrorists as a victory," Chambliss said.
But at least one Republican, Sen. John McCain, pledged that he'd work with Obama and his administration.
"In light of the president's speech today, we will pledge our willingness to work with (Obama) to see that Guantanamo Bay is closed," said the Arizona Republican.
The reproaches didn't only come from the right.
The American Civil Liberties Union's leader -- even as he cheered plans to close the Guantanamo prison and allow for more oversight on drone strikes -- criticized "still insufficient transparency" regarding drones, what he called "unconstitutional military commissions" and the lack of what he'd call a "clear plan" to end "indefinite detention."
"President Obama's efforts to repair his legacy in the eyes of future historians will require that he continue to double down if he is to fully restore this nation's standing at home and abroad," Anthony Romero said in a statement.
CNN's Elise Labott, Chris Lawrence, Barbara Starr and Dan Merica contributed to this report.