WASHINGTON — It was not obvious to the National Security Agency a dozen years ago that Angela Merkel, a rising star as the leader of the Christian Democratic Union, was a future chancellor of Germany.
But that did not matter.
The NSA, in a practice that dated back to the depths of the Cold War and has never ended, was recording her conversations and those of a range of leaders in Germany and elsewhere, storing them in colossal computer databases that could be searched later, if the need arose. It is unclear how often they searched the database for her conversations, if at all.
But once she became the country’s leader, everything she talked about on her personal cellphone - like her support of the Afghan war, the efforts of European allies to halt Iran’s nuclear program, and Germany’s central role in quelling the European financial crisis - took on greater importance for the American eavesdroppers.
How the NSA continued to track Merkel as she ascended to the top of Germany’s political apparatus illuminates previously undisclosed details about the way the secret spy agency casts a drift net to gather information from America’s closest allies. The phone monitoring is hardly limited to the leaders of countries like Germany, and also includes their top aides and the heads of opposing parties. It is all part of a comprehensive effort to gain an advantage over other nations, both friend and foe.
What the United States has learned from Merkel’s calls since 2002, the year when surveillance on her began, according to a database described last week in the German newsmagazine Der Spiegel, remains unknown. But no one has denied that she was being monitored.
In testimony to Congress on Tuesday, the director of national intelligence, James R. Clapper Jr., gave only the roughest sketch of the size of the NSA’s surveillance program, but suggested that the leader of the United States’ most powerful European ally was a single fish in a very big sea.
“We’re talking about a huge enterprise here with thousands and thousands of individual requirements,” he said, using a phrase that appeared to mean individual surveillance targets. Clapper said that the United States spies on foreign leaders and other officials to see “if what they’re saying gels with what’s actually going on,” and how the policies of other countries “impact us across a whole range of issues.”
German political and intelligence officials went to the White House on Wednesday looking for answers to some of the questions the administration has been reluctant to discuss, and eager to use the incident to broker a far closer intelligence-sharing agreement with Washington that, among other things, would end the surveillance of its leaders.
If put into effect, such an arrangement could begin to dismantle a system that has grown ever larger, and more sophisticated, during a decade in which supercomputers and the algorithms used to search vast databases have put the NSA far ahead of rival intelligence services. President Barack Obama has asked whether the technology has outrun common sense, and the Merkel episode has raised in a very public way the question of whether the benefits of spying on friends outweigh the damage if such spying becomes known.
Even after the flood of information about surveillance operations made public by Edward J. Snowden, the former NSA contractor, U.S. officials are still loath to speak in detail about eavesdropping on friendly governments. But former officials with knowledge of the system described an intelligence apparatus with both a voracious appetite and a growing ability to warehouse huge amounts of data.
The NSA tries to gather cellular and landline phone numbers - often obtained from U.S. diplomats - for as many foreign officials as possible. The contents of the phone calls are stored in computer databases that can regularly be searched using keywords.
“They suck up every phone number they can in Germany,” said one former intelligence official.
The databases are different from those housing telephone “metadata” - information about phone numbers on each end of a call and the call’s length - to find links between terrorism suspects.
“Metadata is only valuable if you are trying to track the activities of a terrorist or a spy,” said the former U.S. intelligence official.
By comparison, allied leaders are low-level priorities. In the “National Intelligence Priorities Framework,” a matrix approved by the president and updated regularly, information on members of al-Qaida and other terrorist groups, the whereabouts of nuclear weapons in Pakistan or North Korea, or the conversations of nuclear scientists in Iran are all front-burner intelligence issues.
Ranked just below them are questions about the leadership of adversaries, like Russia, China or Iran, or the state of their economies.
U.S. spy agencies determine how much manpower and resources they can devote to a “target” based on guidelines laid out in the matrix, and each subject is assigned a number from zero to five, with five being the lowest priority level.
But as one former intelligence official put it, “even a low-priority target might be monitored if it’s easy to do.”
At the NSA’s headquarters at Fort Meade, Md., analysts pore over the transcripts of the phone calls and write reports, stamped “top secret,” that are distributed to officials across the government. The most intense interest in the reports is at the State Department, the Treasury, the other intelligence agencies and the National Security Council, former officials said.
But there are still limits to how many of the telephone conversations can be stored, and for how long. Some phone conversations are kept in the databases for weeks, some for months, and some are destroyed almost immediately after they are determined to have little intelligence value.
Clapper discussed the intelligence priorities framework during his testimony Tuesday, partly to point out that the U.S. intelligence services spy only on the people and places they are asked to by policymakers.
Clapper said that National Security Council officials were aware of the spying on friendly governments, without identifying how high up the eavesdropping information goes.
But former officials have said that the raw intercepts, if interesting, would have been included in large briefing books given regularly to Obama’s national security advisers - he is on his third - and their senior deputies, and other National Security Council officials with responsibility for Europe.
“It may not have jumped out at them,” said one former official who knows the process intimately. “But it’s the kind of thing that’s hard to miss.”
The White House has announced that Obama has already assured Merkel that she is not being listened to now, and will not be in the future - though they refuse to talk about the past. The president’s cease-and-desist order to the NSA is an indication that, at least in her case, he now believes that the United States got its benefit-cost analysis wrong.
White House officials have suggested that the entire program of monitoring allied leaders is now under review, although they offer no specifics about which other leaders are no longer monitoring targets.
Meanwhile, Gen. Keith Alexander, the head of the NSA, pushed back in testimony Tuesday at the notion that the NSA was routinely capturing metadata about calls in France and Spain, saying much of that work was done by, or with, allies in NATO. The spokesman for the French government, Najat Vallaud-Belkacem, said Wednesday that “the NSA director’s denials do not seem very plausible.”
A spokeswoman for the National Security Council, Caitlin M. Hayden, said the discussions with the Germans on Wednesday “were an opportunity to hear from one another and jointly determine how the dialogue can best proceed.” The German government has said it will seek an agreement with some of the same elements of the arrangement that the United States has with Britain and other English-speaking allies to share data and refrain from spying on one another.