Whether the Government should increase the financing of pure science at the expense of technology or vice versa often depends on the issue of which is seen as the driving force.

is seen as the driving force需要主语，所以which是is seen的主语，而不是介词of的宾语。所以这是of后接名词性从句作宾语，which为疑问代词，而不是关系代词。

语法结合逻辑，是不难做出判断的。