Let's face facts. If aliens showed up and wiped out all your major population centres on a global scale and the founding father of anonymous managed to upload a virus into the mothership from his mac while the cool guy nukes it you will be lucky if you can find a spanner and trade it for a week old loaf of bread. Some how the world achieved a unified technological recovery and built a huge global military force to oppress the displaced populace while it takes from them what little they have left in a window of twenty years...just in time for the aliens to show up.
So what sort of things might have happened in a realistic version of history?
July 1-4, 1996: Aliens arrive. Global satellite network is destroyed. Most major population centres are destroyed. Manufacturing infrastructure destroyed. Internet ceases. Though the aliens are destroyed the human race has lost its technological powerbase.
Post july 4, 1996: In the aftermath president Whitmore suspends federal elections activating emergency powers declaring himself president for life. The individual ownership of computers ends as governments round up every computer they can get their hand on. Laptops become a black market traded item. The homeless and starving populace are forced into labour camps.
Alquaeda begins construction of UNDERMOUNTAIN, an underground fortress in Afghanistan.
1997: By making use of a Eurasian black market and a network of criminals UNDERMOUNTAIN becomes the centre of a Eurasian spider's Web into which resources begin to pour.
1998: Since the destruction of NORAD and the technological apparatus that gives the United States and other governments a global view and reach, UNDERMOUNTAIN is now the most significant command and control centre in the world. From here Osama bin laden has overseen the acquiring of vast amounts of alien technology recruiting engineers and scientists from across the Islamic world to reverse engineer the technology. He intends to beat the rest of the world to the strategic throne. Fibre optic cables are being stolen. Shipments and warehouses looted. Arms, fuel, and resources are pouring into central Asia. Alquaeda establishes a research airbase of fifty alien 'fighters' which it has recovered. They are hidden beneath Bedouin tents to avoid any prying eyes.
'Miners' salvaging the alien mothership that crashed in Iran begin to feed the alien metal into Iranian smelters. Much of the metal is directed into the manufacture of Iranian arms. Iran rushes to rebuild.
1999: 'Miners' salvaging the alien mothership that crashed in Iran discover an active core. Alquaeda agents on site retrieve the core and smuggle it to UNDERMOUNTAIN.
2000: An airfield in the shadow of UNDERMOUNTAIN is established with a fighter squadron of fifty salvaged alien fighters. Bin Laden orders his fighter squadron to strike at the remaining iranian nuclear research facility. Iranian observers notice the fighters have been painted with the Israeli flag. Iran orders its new destroyer class railgun artillery unit to begin firing on targets in Israel. Fifty ton sub orbital rods of alien metal begin dropping out of the sky over Israel. The kinetic weapons shatter the bedrock destroying entire cities.
2001: The war begins. Refugees begin fleeing the War zone. Iranian railgun artillery bombard Saudi Arabia, Iraq, Syria, and diverse regional populations. The Saudi government relocates to Mecca which it considers a safe zone.
2002: Saudi Arabia begins evacuation of its population to an African colony occupying Ethiopia out of reach of Iran's railgun. Fifty million Muslims have become refugees. They invade Europe clashing with populations over food, land, and resources.
Bin Laden deploys alien fighter squadron to strike at sites across Europe. Observers note they are painted with Russian flags.
2003: Europe mobilises to attack Russia who they now believe have an active alien fighter squadron.
2004: Quake off Indonesia results in a tsunami affecting Indonesia to India. A million Refugees who in fleeing the middle east war and having crowded into the coastal regions in Southern asia are killed by the tidal wave.
2012: Quake off Japan wipes out populations on North east coast as a tidal wave rolls across North Eastern Japan. Half a million refugees crowded into the area around fukashima are killed.
2014: Ebola outbreak in Africa. Without international medical help the virus spreads unchecked. Survivors become carriers of Ebola. Ebola remains active in sperm becoming a sexually transmitted disease.
2015: Ebola spreads uncontrolled in eastern Africa. Without medical help it spreads via sex workers into the 'mining' population working to salvage an alien mothership wrecked on the African Continent. By the end of the year Ebola is pandemic in Africa.
2016: A second wave of Aliens arrive in Earth Orbit. The human race, already on the brink of a well deserved self inflicted extinction are easily eliminated. The mothership in orbit recalls all fighters in preparation for a ground assault. Because this includes bin Laden's fighter squadron, several of which have nuclear devices aboard, the mothership is destroyed in a nuclear suicide bombing.
What this film is, is two days after startrek: beyond. A release date of July 26 as opposed to star trek's July 24 release date.