Ballistic-missile defenses, joint-strike fighters, Black Hawks, and more — Chinese hackers have their hands on plans for these and more of the Pentagon's most sophisticated weapons systems, just the latest sign that the culture of hacking in China continues to put America on the defensive ahead of a tense meeting between President Obama and Xi Jinping, a summit bound to be tense with cyberwarfare diplomacy.

The Washington Post's Ellen Nakashima reports in Tuesday's paper that Chinese cyberthieves have "compromised" mockups that form the "backbone" of some of the U.S. military's most important and high-tech defense technology, and that it could signal a copycat advancement of China's arms, while aiming to "weaken the U.S. military advantage" down the road. The Chinese government, as usual with these attacks — even when they seem connected directly to the People's Liberation Army — are distancing themselves from the pervasive, and this time very internationally unsound, hacking. "The Defense Science Board, a senior advisory group made up of government and civilian experts, did not accuse the Chinese of stealing the designs. But senior military and industry officials with knowledge of the breaches said the vast majority were part of a widening Chinese campaign of espionage against U.S. defense contractors and government agencies," the Post reports.

The new breach comes as a newly disclosed part of a classified Defense Science Board report. Back in January, the board released a public version of the report, warning of possible attacks on U.S. defense systems as well as the Defense Department's lack of preparation and protection. And if you look back in 2005, the same group warned U.S. defense officials against buying microchips from China because of trojan horses and spyware — advice the Pentagon eventually took, cutting off Chinese supply in 2011. But in just the last few months, Chinese hackers have gotten to major U.S. news organizations and government agencies. How have the Pentagon's own cybersecurity experts been so far ahead of the Pentagon's actual cybersecurity if China is stealing our war plans — or at least our warplanes? And is there any way to stop it?

Obama has said that the U.S. military would focus on Asia and the Pacific in the coming year — he called it a "vast and complex undertaking" in his big foreign-policy speech on Thursday. "We cannot look back years from now and wonder why we did nothing in the face of real threats to our security and our economy," Obama said in his State of the Union address this year. Except it may be too late for wonder and speeches; Nakashima reports the Chinese cyberspies already have the basic outlines for the following:

The designs included those for the advanced Patriot missile system, known as PAC-3; an Army system for shooting down ballistic missiles, known as the Terminal High Altitude Area Defense, or THAAD; and the Navy's Aegis ballistic-missile defense system.

Also identified in the report are vital combat aircraft and ships, including the F/A-18 fighter jet, the V-22 Osprey, the Black Hawk helicopter and the Navy’s new Littoral Combat Ship, which is designed to patrol waters close to shore. Also on the list is the most expensive weapons system ever built — the F-35 Joint Strike Fighter, which is on track to cost about $1.4 trillion.

So while that big Mandiant report from February — the one linking a nondescript building all the way to the PLA and back to critical U.S. infrastructure, the one the Pentagon outright blamed on the Chinese government — might be scary, this is a cyber race to weapons building. And it's got implications for future combat: "You've seen significant improvements in Chinese military capabilities through their willingness to spend, their acquisitions of advanced Russian weapons, and from their cyber-espionage campaign," James A. Lewis, a cyber-policy expert at the Center for Strategic and International Studies, told the Post's Nakashima.

According to a report last weekby the Commission on the Theft of American Intellectual Property, a group headed up by two ex-Obama administration officials (Dennis Blair and Jon Huntsman), hacking costs the U.S. some $300 billion per year. And you know what? China is reportedly responsible for a full 70 percent of that when it comes to corporate IP and theft. But a New York Times editorial over the weekend added an important point of emphasis: "While there are concerns about military-related incursions, the focus of most public discussion surrounds hacking into business and industry." Behind the scenes, then, the Pentagon is doing more than it's saying — and building up a more sophisticated cyber battle plan of our own: Wired's Noah Shachtman has an in-depth report today on the Pentagon's so-called Plan X, "a program that is specifically working towards building the technology infrastructure that would allow cyber offense to move from the world we're in today," as Darpa's director put it.

Whether videogame-style protections and clandestine preparations will bail out the Pentagon the next time around, well, we may never know. But we know the U.S. isn't the only victim of military-grade cyber espionage: Australian media reported over the American long weekened that the Chinese had hacked blueprints of the Australian Security Intelligence Organisation's new headquarters. The "blueprints included floor plans and the locations of communications cabling, servers and security systems," reports the Australian Broadcasting Corporation. So, it wouldn't be that hard to imagine China creating U.S. weapons in a building designed by Australia's ASIO, now would it?

Obama is expected to discuss the Chinese hacks — and the widespread culture of hacking in China, which is increasingly looking more like war games than hobby horse — with Chinese President Xi when they meet next month in California. (Update: At his daily briefing, White House Press Secretary Jay Carney said cybersecurity was "a key concern" that would be addressed at the meeting of the presidents, but he deflected questions about the Post report to the Pentagon.) Indeed, there might have to be digital ground rules if we want to keep our planes from taking off over Chinese skies.