America is at a crossroads, in the fight against terror, President Obama said

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 in a counterterrorism speech Thursday.

America prefers to capture, interrogate and prosecute terrorists, but there are times when this isn't possible, Obama said in his remarks 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 it isn't easy, Obama said. While he has considered a special court or an independent oversight board, those options are problematic as well, so he intends to speak 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 that some of the country's actions in recent years -- drone strikes and Guantanamo Bay key among them -- risk creating more threats in the future. 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, while 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.

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 that 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.

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.

He will insist on judicial review from every 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.

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.

It has come under criticism because of its growing cost and a reputation as counterproductive to winning hearts and minds in fighting terror.

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.

"Guantanamo hasn't been a full-time job for a year," one senior administration official told CNN this year in reference to the congressional restrictions on the repatriation of detainees who have been cleared for release.

At Wednesday's daily briefing, White House press secretary Jay Carney said Obama is "considering a range of options" to reduce the prison's population. Senior officials say there is a focus on repatriating and transferring detainees.

"I would say that one of the options is reappointing a senior official at the State Department to renew our focus on repatriating or transferring those detainees," Carney said.

"We're in the process of working on that now; we're looking at candidates" who could lead the process of helping close Guantanamo, Attorney General Eric Holder said this month. "The president has indicated that it's too expensive, that it's a recruitment tool for terrorists, it has a negative impact on our relationship with our allies, and so we're going to make a renewed effort to close Guantanamo."

But with more than half the facility's inmates engaging in various forms of hunger strike, more than 20 of them being force-fed, the failure to close the facility established in 2001 is a continuing problem for the administration.

There are 86 inmates at Guantanamo who have been cleared for transfer, 56 of them from Yemen.

Obama also raised the unpopular topic of foreign aid in his Thursday speech, presenting it not as charity but as a means of national security. It amounts to less than 1 percent 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.

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.

Four Americans killed overseas in counterterrorism strikes

The address built on remarks Obama made in his State of the Union address this year when he said his administration works "tirelessly to forge a durable legal and policy framework to guide our counterterrorism efforts."

It also came on the heels of confirmation hearings for members of Obama's national security team where a pitched political battle over the use of drones was waged.

At Brennan's hearing, Republican Sen. Rand Paul of Kentucky mounted a 13-hour filibuster demanding that the administration detail whether it would be legal to strike suspected American terrorists on U.S. soil.

Attorney General Eric Holder responded in a letter to Paul that the president did not have such authority.

In a letter to congressional leaders on Wednesday, Holder disclosed the administration had deliberately killed Anwar al-Awlaki, an American citizen and radical Muslim cleric who was said to be the face of the al Qaeda franchise operating in Yemen.

Holder said he was actively plotting to attack the United States, and so targeting him was justified legally and from a policy standpoint.

The letter also disclosed that three other Americans were killed overseas in counterterror strikes but that those suspected terror figures were not deliberately targeted by the United States.

In an interview with CNN Chief White House Correspondent Jessica Yellin last year, Obama said the drone issue was a daily "struggle" for him.

"That's something that you have to struggle with," he said. "Because if you don't, it's very easy to slip into a situation in which you end up bending rules, thinking that the ends always justify the means. That's not been our tradition. That's not who we are as a country."

The American public is split on where and how drones should be used, according to a March poll by Gallup.

Although 65 percent of respondents said drones should be used against suspected terrorists abroad, only 41 percent said drones should be used against American citizens who are suspected terrorists in foreign countries.

This number dips even further when the use of drones on American soil is considered. Only 25 percent of people said drone should be used against suspected terrorists in the United States. And when that suspected terrorist is an American citizen, the approval for using drones falls to 13 percent.

Most Americans still support keeping the prison open at Guantanamo Bay.

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 percent said it should be closed.

CNN's Elise Labott, Chris Lawrence, Barbara Starr and Dan Merica contributed to this report