Soren was relaxing in his bed when a pair of men in white labcoats burst through his door, Doctor MacAllan and Doctor Eyre. 
"Sir, we've intercepted the gate commands, they're opening to some place called 'Titania', and it's inhabited!"
Soren sat up quickly and shouted, 
"General Adviser Ortega! Issue Order 141 immediately!"
The General Adviser entered the room with a frightened expression, 
"Are you sure, Commandant?"
A terse nod from Soren confirmed his fears.
"Very well sir, may god help us all."
General Ortega rushed to the war room, shoving past a few secretaries in the hallway. He stopped behind the comms officer and sighed,
"Raise all of the Corps Commanders."
A few minutes went by and then five screens blinked to life with high ranking soldiers standing in them.
"First Army Corps standing by."
"Second Army Corps standing by."
"Third Air Corps standing by."
"Fourth Marine Corps standing by.
"Fifth Naval Corps standing by."

"The Commandant has issued Order 141. This is not a drill."
  All of the Corps commanders visibly paled in response and hesitated for a moment before saluting and their screens went blank.
 "Scan all bands for distress signals."
 Ortega turned towards the hologram of the Earth that floats above the table in the center of the room when suddenly it was nearly entirely covered with red dots indicating devices transmitting distress signals. He gasped and knew at that moment that Order 141 was the only option.

Meanwhile in New Washington...

  The gate opened with a bright green flash and monsters poured out. The soldiers guarding the gate from the civilians turned to see hulking Greenies towering over them. The first few seconds were completely silent as everyone looked each other over, then the Greenies charged forward with terrifying war cries. The soldiers were no stranger to warfare but these were foes like no other. Gunfire erupted through their ranks, Greenies dropping left and right with parts of them missing. A soldier with a large radio pack on was taking cover behind the APC they had arrived in as his compatriots manned it's crew served 20mm cannon and .50 cal machine guns.

  "The gate is open, Command! Monsters are everywhere, we need reinforcements right fu-" 
  The man's transmission was cut off as an axe embedded itself in his skull.
  The soldiers were running out of ammo as the Greenies kept coming and coming. Soldiers were falling left and right, victims of arrows or axes and the little goblins sprinting past them occasionally would jump on civilians and soldiers in groups of three or four and tear the poor soul apart. The rest of the horde stormed past the soldiers as they started to pile back inside their APC to escape the swarm of murderous beasts outside. Once the last of them were inside they stomped on the gas and tore through the streets until they encountered their brethren setting up fortifications around the city. The sergeant asked around and found out the city was being surrounded and that Order 141 had been enacted. They joined the defense as civilians streamed out of the city around them. After about an hour the streams stopped and all that could be heard is the echoing screams of people trapped inside with those things. A rumble in the air set everyone on edge until a wing of A-10 Warthogs few overhead, tearing the city apart with their 20mm rotary cannons. C-130 cargo planes flew over low and slow, dropping pallets of unknown objects into the city. The sergeant, Sgt. Oryn, was pulled down behind cover by another soldier. He was about to ask why when a massive explosion answered his question. More explosions followed and the ground shook beneath him. His ears were ringing and he couldn't hear the planes fly overhead but he could feel the ground vibrating as the A-10s strafed anything that moved in the city, their massive miniguns tearing Greenies in half with a single round. The strafing runs were concentrated around the gate, destroying obstacles and enemies. Suddenly a massive missile flew overhead, flying over the ruined city on a direct intercept course with the gate. At this moment the Greenies decided to make a push, throwing themselves desperately at the soldiers surrounding the city in an effort to escape the death from above but making little progress. Oryn waited for the explosion of the fusion warhead to claim him, but it never came. Little did he know the explosion had claimed plenty.