"Is Buddhism monotheistic?"

In my opinion, no simple answer to this question. There would be a wide range of answers depending upon the person asked and their level of study, aptitude, and understanding, but also the answer goes to what assumptions are made about the question.

Some would say Buddhism is non-theistic, some would say it's polytheistic, and some would say that when it comes right down to it, it is monotheistic, but not monotheistic in the manner of Western traditions.

My personal answer accepts the polytheistic interpretation as metaphor, and to the extent that the divine is everywhere, here and now, yes, poly. It is also non-theistic in that as everything is sacred, nothing is sacred, there's no god or God to worship, everything is worthy of worship and contemplation. The teaching of emptiness.

And I accept Buddhism as monotheistic, the teaching of oneness. There is one God, meaning there is one indestructible reality that is the basis of all being. God, by definition, cannot be any less than the universe, so to envision God as a being or existing in the universe, meaning being smaller than a given space, means that it is not One, not universal.

Of the Buddhist Three Jewels, God is not the Buddha, God is the Dharma. The Dharma encompasses everything. The Buddha is a catalyst, a representative. The Buddha is "smaller" than the universe, smaller than the Dharma. God is the very fabric of the universe, the very essence of anything possibly in existence, and I dare say a whole lot more. Any less, then God is "smaller than the universe". God is the universe. Or specifically, God is the speed of light, but that's a different formulation.

I can't speak of the God in Western traditions, because from what I hear, that God makes no sense, is ridden with human projection, and is, quite frankly, smaller than the universe. But when I read Jewish, Christian, or Muslim works that mention God, I think of this Buddhist idea of God, one as being much bigger and much more incomprehensible than we can ever know cognitively.

Certainly, God is not partisan. When Muslims kill in the name of God, my heart shudders. When Christians refer to the September 11 attacks and say "God bless America", I wish God never blesses anyone like that again.