Say a large alien fleet arrived at earth and just started killing

>>47168624
Depends on how quickly they get the info, but you're looking at at least 15 minutes to scramble jet fighters

In an optimal situation, I'd say 20-30 minutes to get solid confirmation to send in planes and for the to fly there.

>>47168664

So fighters would be able to scramble pretty quickly. What about ground forces?

>>47168697
Depends on the location a lot more. They'd need to be near a military base, but even then you're probably looking at a timescale of hours.

Some things could be brought in with transport helicopters and planes, though not as speedily as jets. I'd estimate roughly 1 hour for the first troop transports to start flying in, with a slow flow after that as more bases get notified and have their troops arrive.

>>47168624
Are they invading only as certain beachhead locations? Or would they be dropping troops everywhere?
Because if they just wanted to kill everything they could just stay in orbit and hit every population center with kinetic bombardment.

If they were only touching down at specific landing sites then I'd say most western nations would be able to mobilize to some extent in a matter of hours.
It would be far easier for us to try and launch nukes at these landing sites, though they would probably just be shot down.

If dropping troops everywhere they could probably defeat humanity in under the 7 hours it took in Half Life. There wouldn't be time for people to reach bases and mobilize properly.

>>47168624
Depends on whether or not reality directed by Michael Bay.

>terrorists illegally cross borsders, start killing authority figures

the state would give them welfare

>>47169231
What if they're white/Christians?

>>47168624
Opening shots of alien invasion: drop asteroids on every major city, military base and power station.

>>47169383

then they'd be statistically more likely to get welfare than the other kinds

>>47169383
They get Burger King too.

>invasion from space
Why the fuck would they not just drop kinetics and wait it out. They don't need to kill us, we'll do it ourselves trying to "survive"

File: 107.jpg (284KB, 1600x1111px)

284KB, 1600x1111px

On a wider scale, after the national guard responds, a US carrier group could be in striking distance in a week maximum. That consists of one carrier, 65-70 aircraft, 2 destroyers or frigates, one cruiser, and a total of about 7500 personnel. This also includes logistical support and a supply ship. Optional submarines and additional frigates, destroyers, and cruisers can accompany a carrier group as well
Assuming the area hasn't been completely overwhelmed by the time they get there, a carrier group is a huge force multiplier.
(Also note, there's usually more pilots than there are birds to fly, so as long as they don't get shot down or run out of fuel or munitions, a carrier can field aircraft pretty non-stop for a as long as they can swap around pilots to fly them)
Iirc Carriers usually come with Marine detachments that serve to protect the strike group.
Pic unrelated

>>47169976
Past this? Historically speaking it can take more than six months to get a military from point A to point B. "A" Being wherever you're military originates from and "B" being actually arriving at the place you want to kill shit.
So on a small scale, the response is pretty fast, but if you want full scale war a la Battlefield Los Angeles (?) It'll takes weeks/months

>>47169383
>What if they're white/Christians?

Then they're already here, paying taxes. I don't think you understand how Welfare predation works, anon.

>>47172928
Maybe they're mass immigrating to japan for the free waifu promotion to improve their birth rate.

>>47168818
> roughly 1 hour for the first troop transports to start flying in
That seems really optimistic; very hollywood or video game. Even the soldiers who live on-base aren't ready to roll at a moment's notice. There are some on-duty fighters and air defense workers, but even in the Cold War, it was assumed that there would be a week or more of build-up before any major event.

I'd say 2+ hours for special forces to leave the ground. Then at least another 4, probably more, for command & logistics to organize a response by traditional forces. After that, it depends on how far the invaders are from the heavy equipment needed to combat them.

the landing site would probably start eating ICBMs within the first hour, but as far as conventional forces go.... lolno. not unless we got lucky enough that the aliens happen to touch down in an area we were ALREADY bombing for unrelated reasons.

>>47168624

If they want us dead, we're dead. They control the high ground, so they can drop rocks, missiles, our own satellites, whatever, onto us. We, trapped in a gravity well, will have a hard time firing back, let alone beating them.

>>47176636
Unless we spin, anon - and the earth spins all the time. Them aliens are fucked by earth's sheev spin.