When the U.S. Department of Defense rolled out its new National Defense Strategy, it put one priority above all others: Rebuilding the military's readiness.

That means new radars for fighter jets, new scopes for rifles and new engines for tanks. But it also means new computer code for everything – even systems deployed 20 or 30 years ago.

"They still have computers. They still have software," said Todd Probert, who leads mission support and modernization programs at Raytheon's Intelligence, Information and Services business. "They still have cyber vulnerability vectors that we need to attend to."

One of Raytheon's roles as a cybersecurity company is to help the U.S. and allied militaries achieve readiness by securing their computer systems and networks. The company's military cyber work includes resiliency for the V-22 Osprey and F-16 Fighting Falcon, as well as the control stations of unmanned aircraft, including the RQ-4 Global Hawk and variants of the MQ-8 Fire Scout. And at the company's Cyber Operations, Development and Evaluation Center, experts scan software and devices for vulnerabilities. They update unpatched code, remove unnecessary software and set up automatic alerts for possible network intrusions.

That kind of work becomes more important as military equipment becomes more computerized and more connected.

"The truth is, we've networked everything," said Bill Leigher, a retired U.S. Navy rear admiral who now heads Raytheon's cybersecurity work for the Department of Defense. From weapons targeting to weather forecasts, he said, "there's nothing that our networks and our software doesn't touch in day-to-day operations."

The problem grows when you consider the vastness of the supply chain, or the manufacturers that build parts of a system such as computer chips. Any one of them, or any of their suppliers, can introduce security flaws.

"You have to understand what the threats are with all of those things," Leigher said.

Making military systems cyber-ready is an increasingly important part of keeping the U.S. and allied forces effective, said Linda Medler, a retired U.S. Air Force brigadier general who served at U.S. Cyber Command and now works as a cybersecurity contractor for Raytheon.

β€œI will always want us to have a leg up on our adversary,” Medler said. β€œCyber gives us that leg, if we use it wisely and appropriately.”