Should the U.S. military focus on China as its potential enemy number one? That argument that erupted on the first day of the Marine Corps’ annual wargame, Expeditionary Warrior 2012. At a panel to prep wargame participants – not just Marines but military officers and civilians from 15 countries – experts ran through an alarming array of threats, from high-tech hacking to old-fashioned naval mines, that could cripple capabilities the U.S. has long taken for granted.

The irony is that the official scenario for “EW12″ isn’t set in Asia at all, despite the administration’s strategic mantra of a “pivot to Asia.” Instead, the wargame takes place in a fictional version of West Africa, with imaginary nations overlaid on real-world terrain, where a U.S.-led coalition must intervene against a well-armed insurgency and the regional powers backing it up – the kind of “hybrid threat” that’s attracted increasing attention among those who think about future wars. But China looms so large these days that it didn’t take long for the Monday morning panel to challenge that focus.

Retired Marine Lt. Gen. Wallace “Chip” Gregson led the charge, outlining a nightmare scenario of conflict across the Pacific from Japan to Taiwan to Guam, with sea-based U.S. forces stretched thin against China’s land-based power. “They have the ability to stretch our defenses at the end of a long logistic line,” he said. “We’ve been accustomed to having secure lines of communication, since 1945,” and where we don’t, as with Pakistan’s closing off key supply routes to Afghanistan, “that’s messing us up.” Equally vulnerable is the globe-spanning infrastructure of satellites, fiber optic cables, and other communications technology that Americans both in and out of uniform have become increasingly dependent on since the 1990s. Both cyber-attacks and precision-guided weapons could rip holes in that electronic web. (This is a problem the U.S. Army is also facing with its JTRS radio program). “We on the American side have become very accustomed to these exquisite communications,” he said. “Is this an advantage or can it be turned into a vulnerability?”

“We very much rely on the electromagnetic spectrum to get our job done,” agreed Rear Admiral Terry Kraft, another panelist. “A lot of our tactics, techniques, and procedures are based on the ability to instantaneously communicate all the time.” If those communications links are disrupted by someone, he went on, without specifically mentioning China, “losing that thousand-mile screwdriver [means] we’re going to have to, guess what, trust our subordinates. We’re going to have to have commander’s guidance… [and] empower our junior leaders so they absolutely know what to accomplish when the coms go down.”

Not all the threats are high-tech, added fellow panelist and naval warfare expert Scott Truver. “The Chinese navy has about 100,000 mines,” he said. “Their doctrine tells us they intend to us them.” Although the new Littoral Combat Ship is supposed to have a mine-warfare “module,” the Navy has generally neglected minesweeping and other unglamorous countermeasures, Truver said; yet “since the end of World War II, mines have seriously damaged or sunk about four times as many U.S. navy ships as all other means combined.”

A new Pacific war has been the de facto focus of the joint Air Force and Navy “AirSea Battle” doctrine, but Gregson called for a much broader perspective on the problem. “AirSea battle does not pretend to be a strategy,” he said. “AirSea Battle is a limited operational concept that focuses on the development of integrated air and naval forces in the context of anti-access area denial threats. [And] to be fair AirSea Battle never pretended to be a strategy, and nobody has written, at least in any open sources I have seen, any strategy for doing this.”

The China specter got some push-back. One officer in the audience asked point-blank whether a conventional war with China was at all likely, given that the two sides are major trading partners – and nuclear-armed. “It’s hard to envision a logical sequence of events that would lead to war with China,” Gregson acknowledged. “Nevertheless there have been events in the past when nations have gone to war when it seemed entirely illogical so there’s an imperative, I believe to prepare… I am not calling for a war against China.”

Gregson isn’t even calling for a new Cold War with China. In fact, he argued that the Pentagon’s nostalgia for Cold War certainties have muddied understanding of the more complex rivalry with China. “A lot of our practices in the Pentagon still indicate we’re searching for a best enemy,” he said. “We don’t have that anymore, and China is not the second coming of the Soviet Union. Virtually all of our friends and allies have a significant economic relationship with China.”

What’s critical, Gregson said, is to get together with those international partners long before a crisis actually erupts. “When the flight time of weapons [in a conflict] is measured in minutes if not seconds, that’s not the time to be putting together the coherent command and control” on the fly, he said. “We need to have the procedures developed, we need to have effective enough training with all of our allies and friends.”