Just weeks after millions of Americans were affected by the largest data breach in U.S. history, the top military leaders in cyber defense met to discuss how best to protect the country's networks and apply cyber capabilities during tactical operations.

The two-day Cyber Security for National Defense Symposium kicked off on Aug. 4 with an address from Adm. Michael Rogers, the head Commander of U.S. Cyber Command and director of the National Security Agency. Rogers was one of more than half a dozen military cyber leaders who spoke during the event, including the Marine Corps' top two cyber officials.  Adm. Michael Rogers spoke to top defense department officials and national security experts as they convened in Alexandria, Virginia, today for the .

The two-day symposium, hosted by the Defense Strategies Institute just outside Washington, D.C., run by the Defense Strategies Institute, carries renewed relevance as the Obama administration government entities redoubles efforts to secure government their networks following a hack of the Office of Personnel Management this summer that compromised more than 21.5 2 million personnel records.

During the symposium, Marine leaders addressed major points of concern during the symposium, including training more cultivating a cadre of cyber warriors, overhauling the Defense Department acquisition process to counter rapidly evolving cyber threats, including better integration of cyber Marines in planning  into Marine Air-Ground Task Force operations planning, and restructuring cyber networks to improve security at home and abroad provide access when deployed.

The Marine Corps is aggressively pursuing solutions to those challenges in part by introducing more cyber lessons into officer and enlisted professional military education, said Col. Gregory Breazile, the director of the service's C2/Cyber and Electronic Warfare Division, who spoke at the symposium. The hope is that future leaders have a better grasp of cyber as they plan operations and secure information, he told Marine Corps Times.

This summer, for example, the Marine Corps hired a "cyber chair" at the Marine Corps University atboard Marine Corps Base Quantico, Virginia, to lead the development of more cyber-themed studies curriculumsaid Col. Gregory Breazile said, the director of the service's C2/Cyber and Electronic Warfare Division who spoke at the symposium

"We have to educate the total force — a cultural change has to happen," he said.

Marines need to be taught, for example, adding that includes ensuring Marines know the risks that come with of browsing social media sites and the boarder internet while using Marine Corps networks at work.

"They are on social media, they click on things and can introduce code to the network," Breazile said. "They could introduce vulnerabilities. They need to understand they are putting others at risk and be held accountable for that."

The symposium was closed to media, and officials with Defense Strategies Institute did not immediately respond to queries about what led to that decision. According to the agenda posted on the Defense Strategies Institute's website, the symposium focused on "policy, operations and technology designed to defend critical networks and allow for the freedom of operation in the cyber domain." according to the event’s agenda.

"Cyber intrusions ... also threaten the ability of U.S. defense and security personnel to operate effectively," the agenda states.