It is time for frank and aggressive action to stop the massive cyber theft of U.S. commercial secrets, as well as attempts to sabotage critical industries and steal defense secrets by hacking via the Internet.

So it was good news that the White House announced on Wednesday it will use fines, trade sanctions and diplomatic pressure to punish nations that steal U.S. trade secrets through cyber spying. The administration also is lifting the veil on its knowledge of those mainly responsible for such theft, and the finger points directly to China — which of course denies the charge.

South Carolinians, more than most, should understand the gravity of cyber attacks. In August, a massive hack into S.C. Department of Revenue files compromised millions of taxpayers’ sensitive data. The department failed to provide adequate cyber security.

The breach of personal data here is a far cry from the theft of sensitive national security data, but it demonstrates the scope of the threat and the need for businesses and individuals, as well as governments, to upgrade cyber security tools.

Considering the additional complication of the country’s tense international relations with China, the federal government’s job is staggering.

A White House conference on the dimensions of the threat from China and other cyber spies came a day after the private security firm Mandiant disclosed that it had traced much corporate espionage to a Chinese military unit located on the outskirts of Shanghai. It is known as “Unit 61398” of the 2nd Bureau of the 3rd Department of the General Staff of the People’s Liberation Army.

China immediately denied the allegation. But Mandiant made it clear in its report that U.S. intelligence agencies possessed the same information. Indeed, it is clear that the White House has known for years that China is behind the theft of American technology by cyber spies. The White House has said it has repeatedly raised the issue in meetings with Chinese leaders, to no apparent avail.

Improving the security of American commercial firms’ use of the Internet is imperative, and President Obama has signed executive orders that will allow closer cooperation between the federal agencies and private-sector firms to speed this process.

But a legal and diplomatic offensive is also needed. Steps have already been taken, with convictions of Chinese firms in American courts for stealing hybrid engine technology from GM and military secrets from L-3 Communications Holdings, Inc., among other cases, the Wall Street Journal reports.

The Justice Department said Wednesday it has obtained convictions in 19 cases against cyber spies stealing trade secrets. Sixteen of these cases involved China. More needs to be done on this front, including fines and trade penalties. Demonstrating a cyber warfare capability would be another deterrent.

China and other cyber thieves are not likely to stop stealing secrets until it becomes too costly, or too dangerous.