President Obama’s promise to “end the Section 215 bulk metadata program as it currently exists” carries overtones of his promise, in January 2009, to close the Guantánamo Bay prison within a year. In both cases, has directed the government to do something, without providing a path to for how to accomplish it.

“This will not be simple,” Mr. Obama acknowledged in his speech. He added, “More work needs to be done to determine exactly how this system might work.”

In the case of Guantánamo, Mr. Obama wanted to find a way to close the prison while not simply releasing those detainees who could not be prosecuted but were deemed too dangerous to release. After Congress, saying he had no plan, blocked him from simply transferring those detainees into a different facility inside the United States, the prison stayed open.

In the case of the bulk call records program, Mr. Obama is saying that he wants to get the government out of the business of collecting and holding all American’s call records, but he wants to preserve the ability of counterterrorism analysts to search through up to two layers of call records, going back several years, for links to a terrorism suspect.

But, as he is acknowledging, there is currently no way to do this. Some of the telephone providers are reluctant to play that role, and requiring firms to change the way they hold their data sets held by different firms could raise new privacy risks. An alternative, creating a consortium to consolidate and hold the data, “would be carrying out what is essentially a government function with more expense, more legal ambiguity, and a doubtful impact on public confidence that their privacy is being protected.”

Against that backdrop, Mr. Obama is directing the intelligence community and the Justice Department to “develop options for a new approach” and report back before the program next comes up for reauthorization by the surveillance court on March 28. He said he would also consult with Congress and seek legislation for the new program as needed.

But in Mr. Obama’s presidential policy directive, there are signs that it may take far longer than that. It instructs the director of national intelligence, by a year from now, to provide a report “assessing the feasibility of creating software” that would allow the intelligence community “more easily to conduct targeted information acquisition rather than bulk collection.”

— CHARLIE SAVAGE