Proponents of a substantial increase in annual funding for the Cybersecurity and Infrastructure Security Agency (CISA) are on the mark given the emergence of cyber conflict as real threat to the homeland and the critical functions U.S. citizens rely on, one of the Senate’s leading experts on cybersecurity said this week.

Sen. Angus King (I/D-Me.) said that the $5 billion budget for CISA touted by Rep. John Katko (R-N.Y.) “is on the right track” because cyber conflict isn’t about a far-off war pitting armies against one another and the same with navies.

“This conflict, the cyber conflict, the target space is in the private sector in the United States,” King said during a conference call with reporters on Wednesday. “The target space is the financial system or the grid or some portion of the grid, or the telecommunications systems. There are any number of targets, 85 percent of which are in the private sector.”

CISA, which is part of the Department of Homeland Security, works with the private sector on a voluntary basis to share cyber threat information and to bolster the cyber security of critical infrastructure entities. The agency also has authorities to strengthen the cyber security of the federal civilian government.

“This is a long way of saying that the establishment of CISA as the essential bridge between the private sector and the government in the conduct of cyber conflict and defending the country is absolutely critical,” King said.

King pointed out that the Department of Defense receives about $745 billion annually whereas CISA has a fraction of that. The agency’s budget is about $2 billion budget and the Biden administration is seeking $2.1 billion for CISA in fiscal year 2022.

Congressional appropriators are recommending an increase between $400 million and $500 million to the proposed budget for CISA.

“What I’m saying is it’s a very important link in a new kind of conflict that I think deserves the authorities and the personnel that will enable them to perform this function that frankly is one that hasn’t been on our horizon for the past 200 plus years,” King said. “We need to, as Lincoln said, ‘disenthrall ourselves’ and think in a new way about how we deal with this kind of conflict and CISA is right in the intersection of how to do it. So, I think adequately funding CISA carefully, tailoring their authorities—we don’t want to create a huge bureaucracy—but we do want an agency that is adequately funded and staffed in order to perform this new but very essential function.”

King was co-chair along with Rep. Mike Gallagher (R-Wisc.) of the Cyberspace Solarium Commission, which ended on Tuesday. The commission made 110 recommendations, half of which have been implemented or close to implementation, including the creation of the National Cyber Director.