I read this book back in the 1990s, and its plot revolved around Japan (pretty sure) going to war with (primarily) the west (although Im sure Russia got involved at some point against Japan).
The main points in the story were Japans technological dominance, their use of a neurological weapon (not a bio weapon) which causes victims to lose all voluntary muscle control, leaving them requiring permanent medical care. The western forces had a new helicopter which used a rail gun as its primary weapon - the rail gun required calibration regularly, and the lack of calibration equipment availability is another main point.
The novel ends in the following way (spoiler based):
Several of the main western characters discover that all the oppositions high tech weapons are centrally controlled, and they all have the ability to be destroyed by that central control point. So they launch an attack on one of these control points in an effect to destroy the neurological weapon primarily - the novel ends with two of the main characters sacrificing themselves after its discovered that each destruct command requires a manual confirmation, and as they don't know the name of the weapon they can't target it directly, so they end up having to essentially start at the beginning and go through a very long list...
I'm pretty sure the title of this novel is something like "The War in 2015/2025/2035" but searches haven't brought up anything.