This is very interesting. I feel like we are in the beginning stages of governments realizing just how valuable these hackers can be and just how brilliant their minds are when they work with technology. Technology has evolved so fast that some countries are running with it and some countries are completely blindsides by what the rest of the world can do. I do believe cyber warfare can be a very serious threat if used correctly. It is something we need to look at when we design our system from here on out.
Cyber warfare can be a threat if the enemy gets hold of information which [ought to] remain secret. For example, when Israel was developing new air defense systems, Chinese hackers got hold of that information and their government quite obviously will use it to make similar or better air defense systems. So, if the enemy learns your weaknesses your strengths through hacking you don't stand a chance against him in battle, would you?
I agree with Redheart, Cyber crime/warfare is indeed a great threat to the world. Cyber terrorism can create havoc to businesses like banks, corporations and multinational companies. They can be used to blackmail people and government. Military secrets are among the most common targets of cyber hacking/crime for obvious reason that they can be used against the government.
Look into Carbanak. It is a malware that has infiltrated the banking system. Hackers have hacked a billion or so US dollars from banks world wide. If a group of hackers can do this and has the determination to do this, then cyber warfare is a great threat. People can find new loop holes or security holes, exploit it, and we won't know what hit us.
Cyber warfare and crimes are the real deal in this age of technology and computers. When you look around, almost all people are on their smart phones, laptops, computers, and gadgets. Cyberspace is already a part of the world, and the access of hackers and cyber-terrorists is widespread. Most defenses and military of countries already have some sort of super computers and computer experts that are ready anytime a cyber attack happens.