The main reason to have an airborne brigade deployable at short notice is for potential NEO ops that can turn ugly. 5 AB Bde in the UK had 2 X Abn bns plus 2 x Air Landing Bns, plus 1 x SAS Tp, Scimitar armd recce sqn, maint, comms etc etc. The aim was to be able to:
a) go to a 3rd world country
b) secure an airfield (and the footprint... my God, the footprint) by airborne assault
c) steal (oops, I mean borrow) a bunch ov vehicles and extract in country nationals, including the conduct of hostage rescue as required
3 Cdo Bde had a similar mandate, and we practises joint ops a few times, with the Marines landing to secure a port facility or other site that we could evacuate from.
We called it 'SPE' ops: Services Protected Evacuation, and we had about 100 contingency plans drawn up for various benighted little countries where UK nationals were labouring away, bless 'em all.
We weren't as big or as fast as the 82nd AB Div, but we could deploy a full brigade group by SHERC within 18 hours, with the LPBG (Lead Parachute Bn Gp) going 'wheels up' within about 8 hours - lead Coy in 6. We planned for 105mm sp by P + 30 minutes, and we had 81mm Mor sp in action by P + 15 minutes, so I was happy with that. As LPBG, if we weren't able to secured the airfield control tower and a decent sized footprint (to deter SA7 attack) within a reasonable amount of time, the Bde Comd was on our ass because we had a few dozen chalks stacked up on their way in.
If the probability of our nationals (maybe not the Lebanese ones?) getting nabbed and chopped up by the locals in the 3rd world is low, then we really couldn't justify it. Eneryone in the whole world LOVES Candians and wouldn't wish us any harm because we're just nice, good guy peacekeepers, right? :
So we probably shouldn't have this, or a similar, capability... I guess?