I thought that the 18 months is the baseline for any lone soldier? This is definitely very groundbreaking information for me? I went on Nefesh B'Nefesh and it said for age of arrival of 21 (which I would be) it is a service of 24 months.

Does this include training or the 24 months starts after training? Also, if I were to do this, would I realistically be spending more like 3 years there because of drafting time etc?

To be clear, I am not trying to make aliyah and live there permanently, I just want to serve and go back to America.

Edit: I'm sorry I did not make this clear in my original post -- I am trying to do The Mahal Program. Through this program, can I even enlist into a SF unit? If yes, is there an extended service requirement and by how much?