LOS ANGELES -- In times of unrest and war, counterterrorism and espionage is a high-stakes world. Often times, intelligence gathering leads to decisions being made.
That's how the Trump administration says it was helped into knowing where drones could take out Iranian Gen. Qassem Soleimani in Iraq.
Before retiring from the CIA, Darrell Blocker spent decades helping recruit and develop undercover sources, many overseas, that would deliver intelligence about potential threats and targets.
Blocker explained recruits volunteer for reasons such as improving their lives.
"Let's just say you're the translator for the president of the country, and he trusts you, but he doesn't really see you, because you're just kind of a piece of the machine," Blocker said. "But for me, because you're in those meetings, because you hear what they're talking about when they're not in front of others, that person might be the most important person in that entire room."
He added that although he has not had one of his own agents die, he has run offices where agents have been lost, and the risk is high in the counterterrorism realm.
"It's dangerous out there. It's dangerous in the Syrias and the Iraqs and the Afghanistans of the world," he said.
In the post 9/11 and digital world, there's also no shortage of cyber intelligence. So much, that the CIA created an entirely new Directorate of Digital Innovation several years ago. And the FBI has a Directorate of Intelligence domestically.
Together, the agencies often share their intel, according to former FBI Special Agent in Charge Steven Gomez.
When it comes to monitoring phone conversations, and even social media accounts, it can be tricky. For the CIA, it's all about location. Gomez says the FBI needs a warrant for a wiretap.
"Espionage is, by definition, illegal, so everything I do in every country that I lived in was questionable from their perspective, but I wasn't breaking any U.S. laws," Blocker explained.
When the target happens to be in the United States, the CIA's partners assist.
"That's where we step in," Gomez said. "And that's why, whenever the FBI has an international investigation, if possible, we want our counterparts at the CIA to participate with us from an intelligence gathering standpoint."
Former CIA, FBI officials explain how agencies spy, gather intel