Could you say labor is forced if you have a choice between starvation and labor? If such is the case, I wish I wasn't forced to work for money in this society and then exchange it for goods and seek out the most favorable deal.
The situation with the Incas was that, without the force coordination necessary to conduct agriculture in the mountains, everyone would die. Where does that fall on the nature versus man spectrum?
The Inca used forced labor to build temples and roads and provide food and other goods to the military. Cooperative farming can certainly become more efficient with additional infrastructure like irrigation and food storage, but I find it hard to believe that the tradeoff here is starvation vs massive cleptocratic absolute monarchy. It went way beyond the need to grow food cooperatively. And in fact, the only way that you would end up with all of this labor available for armies and temples and so on is by generating large food surpluses, so it's clear they weren't on the boundary of starvation. How did I work, I wonder, before there was an emperor?
That said, we currently use money to build roads and provide food and other goods to the military, which we fund through taxes. Taxes are just a more nuanced, easier-to-administer form of "provide x% of your labor to the central authority". The evil part here is the absolute monarchy that makes self-interested decisions about what to do with that labor, but the Inca were hardly alone in that respect.
Oh, no argument against that really. It still falls under the compelled by another man side of the spectrum, but I've long held the belief that collectivist forms of society were necessary in more primitive times.
Only with technological progress are we capable of stronger individualism.
I only mean to answer the question, "Could you say labor is forced if you have a choice between starvation and labor?"
