system
Given the following post, respond as if you're commenting on Reddit:
human
[Independence Day] How did society re-build after the invasion?
gpt
* The largest remaining cities become the new capitals and economic centers. 
* A new set of political elite are drawn from states' civil societies, owing to many politicians dying when their countries' capitals were wiped out.  This new blood along with the extensive infrastructural damage yield dramatic changes to laws and constitutions.  The changes skew conservative owing to the extraterrestrial threat (political attitudes shift conservative under existential threat) and to it being urban rather than rural populations that got wiped out.
* The chaos yields militaristic opportunism, with regional rivals (like Saudi Arabia and Iran) attacking each other and non-governmental forces seizing territory (like in Chechnya).  
* In spite of these incidents, there is a wave of global solidarity as world and regional governmental bodies are created or expanded in light of the extraterrestrial threat.  There's nothing like a common enemy to unite people.
* After a period of time, a reconstruction boom ensues with high levels of employment and economic growth.  There is also heavy investment in military and space-related technologies.  This period is remembered as a golden age of prosperity and development.  
* This boom is aided by the salvage of technologies from the crashed alien ships.  This is therefore not only be a period of prosperity but also rapid technological advancement.  
* Decades later, the earth is scarred but stable.  Humanity has the ability to travel beyond the solar system with technology it still only barely understands.