If there's anything that's pure prerogative it's defense against aliens.

But it would be largely bluff on our part, against aliens that we don't understand.

This might just give us a chance against those damned aliens.

The player is in the role of a lone soldier, who has to fight against aliens that have invaded the earth.

On the Service's jobs was to protect humans against aliens.

"Are we supposed to think that they'd make any practical difference against hostile aliens?"

They stared at the humans and huddled close against larger aliens.

At various points, Bob says he's a government agent, a college counselor, a warrior in the battle against aliens.

It wasn't intended that they should be an advance fighting force against aliens.

But she has also called for tightening the nation's borders against illegal aliens.