What Do I Think of National Service?

Horrible idea.

No active behavior forced on one by another yields positive results.

Moreover, I don't pay taxes so that government can actively tell me that I must go here, or go there, and do a certain thing for a certain period of time.

I say "active" because government does tell us what we may and may not do passively (e.g., we may not murder, we may not steal, we may not build on our property with X, Y and Z permits, etc.). But government's role is supposed to be restrictive in that sense, ensuring a level playing field for all of its citizens.

In our history we have tried this, and recognized its shortcomings -- hence we have no draft, and except in an extreme national emergency, we will not. Draftees are unmotivated to perform at all, let alone at a high level, and the same is true of all who are forced into service.

The only possible way to ensure even the barest minimum of effort is to threaten the use of force against the 'volunteers' -- as they did in the Soviet Union. Otherwise, you must rely on each individual's penchant for the task, or self-motivation, and that's really not worth my tax dollars.