Philip Lieberman, author and CEO of security firm Lieberman Software, believes United States is on the brink of suffering a major cyber attack from another nation state that will severely damage the country’s national infrastructure. The security expert has spoken out as the U.S. falls into its latest bout of international confrontation, with North Korea threatening to launch nuclear attacks on the United States and old foe South Korea. But far more likely than military engagement is the use of cyber weapons, and indeed, the North is already thought to have been behind crippling cyber attacks on the networks of South Korean banks and television stations last the month, reported ITProPortal. The U.S. and the South have taken action to safeguard their digital infrastructures, last week signing a cyber alliance to increase the sharing of strategies and intelligence between the two nations, while President Obama has been busy bolstering the U.S. cyber arsenal and acquiring legal permission to launch cyber strikes this year.