The tier system in the SF context refers to the asset tasked for the mission and is linked to readiness, not necessarily just about core competency. The Rangers are better suited and equipped for rapid incursion in support of their tier one (primary) counterparts. Green Berets tend to deploy in smaller self contained units and are dotted around the globe, their role is (or used to be) different and more subtle than that of a hard hitting Ranger Battalion on immediate standby to deploy out of Fort Bragg. Most young thrusters do Ranger selection and attachment then go on to the Green Berets, often after time in the latter they may then opt for tier one selection.Working out of memory here but isn't it the other way around with Rangers being Tier 3 and SOF being Tier 2?
In the end the ranger regiment is a premier airborn capable light infantry regiment and has (as you stated) often a supporting role or conducts things like securing an airfield and such (Very simplified I know )
'Green Berets' are usually the guys the US sends on covert/overt training missions. Pakistan, Somalia, Colombia, Phillipines etc .... often fighting alongside. They're an integral part of US foreign policy.i dont realy know much about the green berets but i would like to know more
what i already know is that they are usualy boots on the ground before any major assualt force or surgical strike force doing reconisance and or targeting assets linked to the opposing side