WASHINGTON — Every day for one month last fall, Jonathan Sallet, the general counsel at the Federal Communications Commission, sneaked into a small, windowless office at the agency, its location undisclosed except to senior staff.
From 6 a.m. until early evening, with Bach streaming in the background, he worked mostly alone, marking up stacks of law books and standing in front of a lectern. His job: Defend in court the F.C.C.’s most contentious policy — rules to classify broadband Internet providers as utilities, widely called net neutrality.
“I did nothing for one month but prepare,” Mr. Sallet said in an interview. “I talked a lot to the wall.”
His arguments, though — like nearly all of his actions for the agency — have had far-reaching reverberations.
In his two years as the F.C.C.’s general counsel, Mr. Sallet, 63, has taken center stage in some of the most divisive debates in Washington. He helped shape and then defend the net neutrality law. His input helped kill the Comcast-Time Warner Cable merger last year. In recent days, the cable industry has closely tracked his thinking about a merger between Charter and Time Warner Cable, concerned about a similar result.
“Typically a general counsel is like an administrator,” said Reed Hundt, a former Democratic chairman of the F.C.C. “But in Jon you have an administrator who is also a policy maven and political strategist.”
Mr. Sallet will draw more of the spotlight in coming months, a period that could shape the tech and cable landscape for years to come. The agency is set to take a position on the Charter and Time Warner Cable deal, as well as vote to open the market of set-top cable boxes to new competitors. And the decision in the net neutrality case, the one he prepared so long and hard for, is also expected.
Each weekday morning, Mr. Sallet is among a small cadre of top advisers who meet at 8:45 to discuss policy and strategy with Tom Wheeler, the chairman of the F.C.C. Mr. Wheeler, a former lobbyist for the cable and wireless industries, knows firsthand how the agency’s actions can be derailed by the pressure of lobbying by the powerful businesses he used to represent.
“He is a multifaceted talent with the ability to see all angles of an issue and provide sage counsel,” Mr. Wheeler said of Mr. Sallet.
In the recent interview in his office, where the slim and soft-spoken Mr. Sallet keeps a keyboard and guitar, he said swift changes in how people communicate and consume media have thrust the agency — and him — into the spotlight.
For decades, Mr. Sallet has been an inside player in telecom policies. After graduating from law school at the University of Virginia and working as a clerk for Justice Lewis F. Powell, he spent 30 years representing companies like MCI and working on tech policy at the Commerce Department.
While at the Commerce Department, he was introduced to the Mosaic web browser by Vice President Al Gore. That was in 1993, the same year Mr. Wheeler showed him a demonstration of a wireless phone.
These days, Mr. Sallet said, policies related to smartphones and the Internet get such strong reactions that they require more than a broad view of economics and markets. They also require an ability to navigate pointed political criticism.
That climate makes sticking to a set of principles all the more important, he said. For him, those ideas are that networks should be open for consumers and that the F.C.C. should “take actions to avoid a society of haves and have-nots.”
Net neutrality “involves competition issues, the mergers are quite clearly about competition,” he said.
Mr. Sallet’s stance has not slowed criticism. The F.C.C. recently proposed an overhaul of the TV set-top box market, a move that could open a new area of business for tech giants like Google and Amazon. Cable and media companies are fighting the plan, saying it would erode the core of their business.
In addition, some academics criticized the agency’s decision last spring to block Comcast’s merger with Time Warner, after a review led by Mr. Sallet. Critics said the companies did not compete in the same markets and would not reduce the number of options for consumers.
The review of Charter’s acquisition of Time Warner Cable is expected to yield a decision this spring. Though analysts are generally confident it will be approved, the agency is likely to attach several requirements that ensure the merged company doesn’t use its size to keep programmers from offering content to streaming providers.
The harshest criticisms have been for Mr. Sallet’s role in advising and writing up net neutrality policy — with technology and telecom companies arguing that Mr. Sallet, a Democrat, has made too many decisions based on politics.
In October 2014, Mr. Wheeler, also a Democrat, introduced rules that could have let cable and telecom firms carve the Internet into various high-quality and low-quality tiers, according to some legal experts and net neutrality advocates. Top officials at the agency were reluctant to create stronger rules that ban such practices by regulating Internet service providers like utilities.
Mr. Sallet had talked in public about a desire for a middle ground “hybrid” rule that prevented broadband providers from blocking or unfairly slowing down traffic but didn’t expand the agency’s regulation over the industry. That middle ground was quickly attacked by many net neutrality advocates, drawing millions of comments of protest, many of them inspired by a late-night monologue by the comedian John Oliver.
The pressure intensified the next month, when President Obama took the unusual step of saying that broadband service providers should be treated like utilities, subject to rules akin to those placed on phone services. Soon after, Mr. Wheeler directed Mr. Sallet to rewrite the draft rules to more aggressively regulate the Internet service providers.
“Ultimately Jon is the lawyer and Wheeler is his client,” said Robert D. Atkinson, president of the Information Technology and Innovation Foundation.
To complicate the situation, the rules were almost guaranteed to face strong legal challenges. Telecom and cable companies immediately sued to overturn the regulations, and the case was handed to the United States Court of Appeals for the District of Columbia, the same court that had struck down net neutrality rules twice before.
Mr. Sallet made his arguments defending the latest rules in December, winning plaudits from all sides for his work in the courtroom. A decision is expected this spring. Other legal challenges to the policy are likely.
Mr. Sallet and his supporters said his positions, and those of the F.C.C., should not come as a surprise. Mr. Sallet and top advisers have talked frequently about the agency’s push to keep big telecom and cable firms — which control the video and broadband pipes into homes — from stifling new technologies.
There are even echoes of this philosophy in a speech he helped write in 1994 for Mr. Gore. In the speech, at University of California, Los Angeles, Mr. Gore called for an overhaul of rules for phone and cable communications to encourage the development of the coming Internet economy.
“We look back now and see that was incredibly prescient,” Mr. Sallet said.