There are few topics in Washington more urgent than cybersecurity. For months it has dominated the headlines, from the fallout of the thousands of classified documents leaked by Edward Snowden, a former National Security Agency contractor now hiding in Russia, to high-profile hacks of U.S. media Web sites, including The Washington Post.

Government and private computer networks safeguarding everything from weapon designs to credit card numbers are under constant attack. Often cyber thieves want to steal trade secrets, information or money. But cyber experts say the hackers increasingly also want to disrupt and destroy.

William J. Lynn III, a former No. 2 at the Pentagon, said another trend is that it’s not just “sophisticated nation-states” that have potent cyber-capabilities. Now posing a significant threat, he said, are the likes of “a dozen guys in flip-flops with Red Bull.”

Lynn and other experts who spoke at The Washington Post’s Cybsersecurity Summit on Oct. 3 are excerpted in this special report. Video highlights are also posted on Much of the discussion focused on the growing cyber threat and the need for private companies to work with the government to forge the strongest defense.

Rep. Mike Rogers (R-Mich.), chairman of the House Intelligence Committee, said he was frustrated by the damage the Snowden leaks have caused at a time when “the threat matrix is rising.” He noted that the private sector controls 80 percent of the networks in this country; it is vital to our national security to protect those cyber networks that control our transportation, banking and other crucial systems.

As James Andrew Lewis explains in his article in this section, “economies depend on the Internet and a growing number of services and devices — from factors to cars — are connected to it, making it an irresistible target.” Lewis said the United States may have the best offensive cyber-capabilities in the world, but needs to work on its defense.

The nation that brought you the Internet — and has been so enriched by it — now has the most to lose from attacks on it.