But those on the front lines say it isn't all about protecting US government and corporate networks from a single sudden attack. They report fending off many intrusions at once from perhaps dozens of countries, plus well-funded electronic guerrillas and skilled criminals.
Security officers and their consultants say they are overwhelmed. The attacks are not only from China, which Washington has long accused of spying on US companies, many emanate from Russia, Eastern Europe, the Middle East, and Western countries. Perpetrators range from elite military units to organised criminal rings to activist teenagers.