Standing beside Chancellor Angela Merkel of Germany on Friday at the White House, President Trump told her, “at least we have something in common.”
Mr. Trump was comparing himself to a foreign leader whose cellphone calls had been intercepted by the National Security Agency. He was doubling down, once again, on his much-disputed claim that his calls, too, had been wiretapped on orders of President Barack Obama.
It was the latest in a series of extraordinary statements in which Mr. Trump, with awkward support from his aides, took an unusual stance for an American commander in chief: He spoke not as the boss of the intelligence agencies, but as their victim.
Even if his wiretap claim was groundless, as seems all but certain, it has unexpectedly renewed a debate on the left as well as the right over whether security agencies invade Americans’ privacy and could undermine democracy. Whether the president intended such a discussion or even welcomes it, his repeated undercutting of the spy agencies has been striking.
Shortly before taking office, he infuriated intelligence officials by comparing their agencies to Nazi Germany. In February, he suggested that intelligence leaks were “just like Russia”; his aides, with his encouragement, have pushed the idea that the “deep state” of security agencies sought to undermine his presidency.
If such charges were previously unseen in the history of the American presidency, so were the circumstances in which Mr. Trump took office. In a public report before his inauguration, the intelligence agencies concluded that Russian hacking and disinformation were intended to help him defeat Hillary Clinton. He bitterly resisted the claim, which cast a shadow of doubt over the legitimacy of his victory.
All of those tensions will be in the air on Monday, when the leaders of the F.B.I., James B. Comey, and the National Security Agency, Adm. Michael S. Rogers, testify before the House Intelligence Committee. Mr. Trump’s wiretap accusations are certain to come up.
Constrained both by classification rules and by deference to the president, the intelligence officials will have to pick their way carefully through secret intelligence programs and Mr. Trump’s attacks.
Of all of Mr. Trump’s Twitter eruptions, his March 4 outburst on surveillance may have been the most disturbing, both for those who believed it and for those who dismissed it as outrageous nonsense.
“How low has President Obama gone to tapp my phones during the very sacred election process,” Mr. Trump asked, with erratic spelling. “This is Nixon/Watergate. Bad (or sick) guy!”
The claims, denied by Mr. Obama, have been definitively discredited by intelligence officials and members of Congress in both parties. When the president’s spokesman, Sean Spicer, floated a new theory that Mr. Obama had enlisted British eavesdroppers for the illicit job, British officials indignantly denied it, and the White House quickly backed down.
In the face of bipartisan pushback, the president has refused to relinquish his claims.
Many of Mr. Trump’s critics have dismissed the tweets as an impulsive reaction to things he read on the internet. Some of his vocal critics believe that the wiretap gambit is a deliberate attempt to create a distraction from the many challenges facing his young presidency.
It could also be that by pre-emptively discrediting the F.B.I., C.I.A. and National Security Agency, he is hoping to undermine any damning evidence they may produce of his associates’ contacts with Russia. In the domestic sphere, after all, he and his aides denigrated the Congressional Budget Office in anticipation of the office’s dismal projections on his health plan.
Or possibly the president’s repeated battering of the intelligence agencies is not so different from his attacks on the Environmental Protection Agency or the State Department. He may view the spy agencies as just additional targets in what his adviser, Stephen K. Bannon, calls the “deconstruction of the administrative state.”
“It’s in keeping with his attitude toward government in general,” said Elizabeth Goitein, a director of the liberty and national security program at the Brennan Center for Justice. “He has nothing but antipathy for the agencies he controls.”
Yet Ms. Goitein, who has no sympathy for Mr. Trump’s policies, believes his clumsy comments on wiretapping, even if not true, should be an opening for a broader discussion of government surveillance and American privacy. She is among the civil libertarians who believe Mr. Trump’s critics have been too quick to dismiss the real possibility that the National Security Agency or F.B.I. might actually have picked up Trump campaign communications under eavesdropping rules that civil libertarians see as too permissive.
“I don’t think we can laugh it off,” she said.
Intentionally or otherwise, Mr. Trump has rejuvenated the debate over the proper balance of privacy and security that surfaced after Edward Snowden’s disclosures about N.S.A. programs in 2013. When the libertarian Senator Rand Paul, Republican of Kentucky, used the Trump claims to suggest a broader concern about privacy, Glenn Greenwald, a left-wing writer for the online publication The Intercept, backed him up in a column titled “Rand Paul Is Right.”
“Paul’s explanation is absolutely correct,” Mr. Greenwald wrote. He said that the National Security Agency “is empowered to spy on Americans’ communications without a warrant,” calling current procedures a violation of the Fourth Amendment and “the dirty little secret of the U.S. Surveillance State.”
What these odd political bedfellows were pointing out is a truism inside the intelligence world but less understood outside it: When the National Security Agency or the F.B.I. eavesdrop on foreigners’ communications, they often pick up the Americans who are talking to them. National Security Agency and F.B.I. officials call this “incidental” collection, but it can have serious consequences.
It appears that such incidental collection, for instance, decided the fate of Michael T. Flynn, who stepped down as national security adviser after he was picked up talking to the Russian ambassador, Sergey I. Kislyak, and lied about the conversations.
To address the threat to American privacy from incidental collection, the government applies what it calls “minimization” rules. Names of Americans must be masked in intelligence reports disseminated by the agencies, but there are exceptions: Officials can request that the names be unmasked to help understand the reports, and the names are available to criminal investigators.
There is also the possibility of what is called “reverse targeting” — say, eavesdropping on Mr. Kislyak, ostensibly to find out what the Russian ambassador is up to — but with the real goal of catching Mr. Flynn. Reverse targeting is prohibited by law, but Ms. Goitein points out that it is difficult to prove because it requires showing what was in the eavesdropper’s mind.
In addition to the targeting of specific foreigners, several N.S.A. programs sweep up huge quantities of communications wholesale. According to the rules, intelligence officers apply privacy protections later, when they conduct searches of the data.
The volume of communications available for searching can be mind-boggling. In 2011, the National Security Agency collected and stored 250 million internet communications from a single program, known as Section 702, according to a report from the government’s Privacy and Civil Liberties Oversight Board. In 2015, the same program targeted more than 94,000 foreigners — and carried out more than 23,000 searches of its data for “U.S. persons,” meaning citizens or permanent residents. Many Americans inevitably turn up in the data, either because they are communicating with a foreigner or are mentioned in a foreigner’s messages.
Under the Section 702 program, the National Security Agency and the C.I.A. can use American names to search its data if the query is “reasonably designed” to find foreign intelligence. The F.B.I. can do the same not just to find foreign intelligence but also to find evidence of a crime.
Civil libertarians believe those rules are far too loose. The Snowden revelations forced intelligence officials to be far more open about their procedures, but few Americans are aware of the extent of the incidental collection of their emails and calls.
David Medine, who was chairman of the Privacy and Civil Liberties Oversight Board from 2013 to 2016, is a supporter of stricter rules that would require court approval for such searches. He noted that the normally five-member board, which by statute has subpoena power and access to even the most classified material, currently has only one member and is awaiting nominations from Mr. Trump before it can resume its work.
“If the president is concerned about surveillance by the intelligence agencies,” Mr. Medine said, “one thing he should do is appoint new members to the board.”