Speaking of Taiwan, a newly disclosed U.S. intelligence assessment describes American concerns that China might be developing sophisticated weapons to zap the self-governing island’s electronics, or perhaps to use against an American aircraft carrier in the Taiwan Strait.

The 2005 assessment by the National Ground Intelligence Center, part of the Army’s Intelligence and Security Command, details China’s experimentation with electromagnetic pulse and high-power microwave weapons, either of which could theoretically be used to shut down the communications systems and other electronics in Taiwan.

The report, obtained by the National Security Archive, an independent non-governmental research group, said that Chinese researchers had been conducting tests on animals with the technology but that the “real purpose was to investigate potential human effects of exposure to these specific radiations.”

Three years ago, James J. Shinn, a senior U.S. defense official, warned of China’s development of electromagnetic pulse weapons, telling a House committee that China was known to be working on related technology. The United States “could be in a very bad place if the Chinese enhanced their capability in this area,” he said at the time.

Unlike an electromagnetic pulse weapon (EMP), which could deliver a burst of energy similar to that produced by a nuclear blast, a high-power microwave weapon (HPM) would produce a narrower but still powerful beam of energy.

The United States and other governments have long worked to perfect high-power microwave technology.

The problem, experts say, is that it’s been difficult to make the weapons both safe and effective. An HPM device would have a range of only a few hundred yards; weaponry that was designed to have a greater range could effectively set the atmosphere on fire.

“People have been talking about these things for many decades and they just haven’t gone anywhere,” said John Pike, director of GlobalSecurity.org, a defense think tank.

All the same, given U.S. research efforts, Pike said it wasn’t surprising that the Chinese were pursuing the technology.

“One would be amazed if they were not doing this sort of thing,” he said.

The 2005 assessment envisioned a “Taiwan Scenario,” whereby the Chinese might believe that an attack to destroy the island’s electronic infrastructure would minimize casualties and lessen the likelihood of a nuclear response by the United States, which is legally bound to provide for Taiwan’s defense.

The National Security Archive made the 2005 assessment available as part of a large new cache of U.S. intelligence documents on China.

More of the records can be found here.