Nope. Not that kind.
And if you don’t know where that image comes from, you’ve missed a hell of a book.
So, the question is … Could our current technology repel an alien invasion?
I see only two negatives. 1) our weaponry is (by the vast majority and nearly all deployed) kinetic in nature. Either explosive or projectile. And 2) our range is limited by its designed use. Which is to say, our existing weaponry (as a planet, not necessarily as a nation) is designed for a rather sub-orbital use.
The limited range of our weapons is not completely a definitive answer to the question however as (and we all know this) you cannot successfully invade that which you do not put troops on.
Additionally, with our technology, we’ve certainly not established a known (even theoretical) defense to kinetic weapons.
However, the lack of the high-ground is a certainty. This is not meant to be a dig directed at the fall of NASA, but generally speaking we do not have anything in the way of planetary defense. And I’m not really suggesting there should be as there is no evidence that such would ever be needed. I’m simply pointing out that none exists.
So, we’d be left to mount a defense from the surface. Most science fiction (being written by American authors) tends to assume the US being the focal point for the invasion. I would agree to a point. I would think, from orbit and without an understanding of our radio transmissions, there would be two main points of attack. One, of course, being the US and the other being Europe. Europe would likely get hit due to the density of civilization apparent from a distance. The US a target due to the large amount of radio transmission whether the invaders understand it or not.
There is another tactic which the book related to the picture above mentions. The middle of the US. The farmland. The central US is the largest (at least on our half) unbroken, massive area of agriculture on the planet, easily determined from space if you’re looking hard enough. The aliens in the above story figured it would make a perfect location for a beach-head as no species would knowingly and intentionally damage or destroy its own food supply.
In the story, as well as I believe we would in reality, we nuked them.
Now I’m not going to get into spoilers about that particular story but I really do think we would. At least until the fighters among us were killed and we’re left with nothing but cowards.
So what do you think?
Could we survive? What sorts of aliens do you envision? Would it be a short fight (years) or a long one (decades) or a new way of life (generations)?