There were no Geneva Conventions at the time of the Revolutionary War. Additionally, the Geneva Conventions apply to states, not to revolutionary groups. Some revolutionary groups, who by definition aspire to state power and to be accepted by other sovereign governments, will act in accordance with norms of civilized behavior. Others will not. That's not the issue.
"Any means necessary"? Are you saying that if you were backed into a corner, you would kidnap your neighbor's children, kill one, and then hold the second one hostage in order to save your life? Would you shoot a woman in the back for committing the crime of seeking drinking water - because doing so, in your mind, increased the chances of your surviving? Would you take your neighbor's mother hostage and threaten to kill her unless your neighbor drove a truck full of bombs at your enemy? Would you torture your neighbor's sister in order to gain your neighbor's obedience?
Today, apparently innocent Iraqis died when their van approached a Marine checkpoint and ignored orders and warning shots. The Marines pulled the triggers, but the victims were killed by Saddam's Fedayeen. It is understood that the violator is liable for whatever resultant casualties and suffering - and that responsibility extends to the commanders who gave the orders. It is also understood that soldiers in civilian clothes are subject to summary execution on the spot - though the US is unlikely to rely on that right. On a larger level, a country that makes such criminal behavior its national policy loses whatever claims to legitimacy and recognition that it might have had.
