indeterminable

adjective [原级]不能解决的；不能确定的

The problem with this, for Stalin, was that it would have delayed what he viewed as the "final global victory of Communism" for an indeterminable period.
对于斯大林而言，这一做法存在的问题在于，它会将他认为的“共产主义在全球范围内的最终胜利”推迟到一个无法确定的时期。