One hundred years before Ender's Game, the aliens arrived on Earth with fire and death. Earth Afire by Orson Scott Card and Aaron Johnston is the story of the First Formic War.
Victor Delgado beat the alien ship to Earth, but just barely. Not soon enough to convince skeptical governments that there was a threat. They didn't believe that until space stations and ships and colonies went up in sudden flame.
And when that happened,

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"The war may be over, but "Black Jack" Geary and his newly christened First Fleet have been ordered back into action to investigate the aliens occupying the far side of Syndic space and to determine how much of a threat they represent to the Alliance."--from publisher's description.

Avice Benner Cho, a human colonist on a distant planet populated by the Ariekei, sentient beings famed for their unique language, returns to Embassytown after many years of deep space exploration to find she has become a living simile in the Ariekei language even though she cannot speak it, and she is torn by competing loyalties when hostilities erupt between humans and aliens.

"Growing up, Travis Uriah Long yearned for order and discipline in his life...two things his neglectful mother couldn't or wouldn't provide. So when Travis enlists in the Royal Manticoran Navy, he thought he'd finally found the structure he'd always wanted so desperately. But life in the RMN isn't exactly as expected. Boot camp is rough; his first ship assignment lax and disorderly; and with the Star Kingdom of Manticore still recovering from a devastating...

Ace intelligence operative Lt. Jazen Parker parachutes into Tressel, a planet which resembles Earth in its Paleozoic era, on a mission to bring down the local politicos. He quickly realizes hes been handed a near-impossible task. Tressel is a politically-quarantined nightmare world with a culture confined to iron rivet technology and a ruling regime a bit to the right of Heinrich Himmler. Jazen is inclined to abandon this particular hellhole to its...

"The Solarian League lies in defeat, crushed by the Grand Alliance of Manticore, Haven, and Grayson. Obedient to the Alliance's surrender demands, the League is writing a new Constitution, to prevent the reemergence of out-of-control bureaucrats, like the "Mandarins" who led it to disaster. Frontier Security has been disbanded, the Outworlds' have regained control of their own economic destinies, and multiple star systems will soon secede from the...

The planet Lusitania is threatened with destruction by Starways Congress. With the help of the computer intelligence Jane, Ender must save the planet and its three species.

"Caught up in a space station turf war between gangs and corrupt law, a lone asteroid miner decides to take them all down. When an asteroid miner comes to Station 35 looking to sell her cargo and get back to the solitude she craves, she gets swept up in a three-way standoff with gangs and crooked cops. Faced with either taking sides or cleaning out the Augean Stables, she breaks out the flamethrower."--Publisher.