WASHINGTON — Of the many questions left unanswered by the American intelligence agencies’ accusation that Russia’s president, Vladimir V. Putin, led a multilayered campaign to influence the 2016 presidential election, one stands out: Why did it take the Obama administration more than 16 months to develop a response?

The short answer, suggested by the report the agencies released on Friday, is that the United States government is still responding at an analog pace to a low-grade, though escalating, digital conflict.

The report, compiled by the F.B.I., the C.I.A. and the National Security Agency, makes no judgments about the decisions that the agencies or the White House made as evidence of Russian activity mounted. But to anyone who reads between the lines and knows a bit of the back story not included in the report, the long lag times between detection and reaction are stunning.

The delays reveal fundamental problems with American cyberdefenses and deterrence that President-elect Donald J. Trump will begin to confront in two weeks, regardless of whether he continues to resist the report’s findings about Russia’s motives.

Source: U.S. Reacting at Analog Pace to a Rising Digital Risk, Hacking Report Shows