Jessica Estepa

USA TODAY

President Trump is well-known for waking up early, watching cable news and firing off short missives on Twitter about whatever he's thinking that day.

With a waiting audience of 30 million followers, Trump denounces certain media organizations as "fake news," extols his own victory in the presidential election, and criticizes decisions he disagrees with, including his own Justice Department's appointment of a special counsel for the Russia investigation – which he's called a "witch hunt."

Trump has been hailed by his base for his use of Twitter as a direct and unfiltered look into how he operates. But his robust online persona isn't just open for American voters to analyze: Foreign intelligence agencies are also likely paying close attention, which may be especially useful as Trump makes his way along his ambitious five-city first foreign trip, says one expert.

"Imagine you're a foreign leader about to meet the president," said Tom Nichols, a professor of national security at the U.S. Naval War College who is also a specialist in Russian affairs. "You'd want to know, 'What kind of man am I about to talk to, what things flatter him... How do I manipulate this meeting in my best interest?'"

Indeed, foreign governments are paying close attention to detail to keep the president happy during his trip abroad.

The Associated Press reported how, in Saudi Arabia, caterers reportedly were planning to serve steak with a side of ketchup — the president's favorite meal — alongside local cuisine. And The New York Times reports that foreign dignitaries were encouraged to compliment Trump on his electoral college win and compare him favorably to former President Obama. These, of course, are topics he frequently discusses on Twitter even months after winning the election.

It's a regular practice for intelligence agencies to create profiles on world leaders based on public information. Back in 2015, for instance, USA TODAY reported on a 2008 study from a Pentagon think tank that theorized Russian President Vladimir Putin has Asperger's syndrome. While Putin has denied this, that study, along with another report from 2011, concluded that Putin's body language shaped how he makes decisions and reacts to events.

According to the reports, Putin appears to have physical difficulties, hypothesizing that he may have suffered a "huge hemispheric event event to the left temporal lobe of the prefrontal cortex" of his brain, possibly in utero. "His primary form of compensation is extreme control," the 2008 report reads. That is "reflected in his decision style and how he governs."

Just as there's presumably a ton of open-source intelligence available from videos of Putin's movement patterns, for any person or organization looking to better understand Trump, one can glean a lot of information from his tweets, Nichols said.

From his early morning and sometimes late night tweets, people can pinpoint roughly when the president wakes up and when he goes to bed. And it's possible to make an educated guess what networks he likes to watch and what subjects he is most interested in, depending on what he's responding to. (Using this same logic, USA TODAY conducted its own analysis of the president's first 100 days of tweets in office.)

"Not one of those things is important by itself," said Nichols, who explored this idea both on Twitter and in a piece he wrote for the Federalist. "But together, they create a cohesive package of a daily rhythm." Understanding these details means one could make educated guesses about how the president would react in moments of crisis — or even in the kinds of diplomatic situations the president has found himself in during his foreign trip this week.

It's one big reason why world leaders don't use social media as often – or, at least, are less unfiltered about what they put out to the world, said Nichols, who had fundamentally the same concern about emails released from Hillary Clinton's private email server. They revealed personal details that seemed inconsequential but could be useful to foreign governments.

Amid the controversy over Clinton's use of her own email server during her time as secretary of State, the agency released thousands of pages of her emails. While much of the discussion (and FBI investigation) focused on the digital security of Clinton's server and whether the former secretary of State inappropriately handled classified information, there's would also be some risk if her personal details are exposed to the world – even if it's just about how much she likes the TV show The Good Wife or how she takes her tea.

"That stuff is gold," Nichols said, for foreign intelligence agencies.

Of course, there's no way to know the full spectrum of information other countries may have about Trump.

"Let's put it this way: There's no way the president's tweeting is bad for foreign intelligence agencies," Nichols said.