One of the most innovative actions discussed inside the intelligence agencies, according to two officials familiar with the debate, involves finding a way to breach the so-called great firewall, the complex network of censorship and control that the Chinese government keeps in place to suppress dissent inside the country. The idea would be to demonstrate to the Chinese leadership that the one thing they value most — keeping absolute control over the country’s political dialogue — could be at risk if they do not moderate attacks on the United States.