Who are insurgents, radicals, and militants?

Who are insurgents, radicals, and militants?
In relation to Afghanistan?
I’m writing an essay and getting the terms all confused.

Corrrect me if I’m wrong –
Insurgents are the people trying to take out the US military in Afghanistan.
Radicals are the Islamic extremists who are doing the same thing as the insurgents, but to the whole world
And militants are the US soldiers?

thank you!

Ah the web we weave. Insurgents are more associated with the “insurgency” or surge of violence within Iraq although the name for some reason has carried over to Afghanistan to just generalize anyone who puts up resistance to the Coalition forces fighting within this country (speaking from where I’m sitting right now in Afghanistan). Radicals is specifically used in Afghanistan’s case to identify Taliban fundamentalists or religious clerics who are unwilling to compromise. Likewise in the past we have used the term “radicals” to identify US religious clerics, or leaders whose actions are not redeemable (Jim Jones and Jonestown). While the term “radicals” is not specifically utilized to describe persons with a religious setting, for some reason we have resorted to this. Lastly militants are individuals with military training or skill sets, but not associated with a national army, as with the Northern Alliance, and the Mujahideen . As I have stated before these terms are all loosely based as it allows for leniency in identifying potential political targets, or prisoners. I hope this helps.