did laser weapons,like the AER9 come before or after the great war...if after why arent they spending there time,and money on restoring the country.

Laser weapons were brand spankin' new at the start of the great war, being just initally released to law enforcement IIRC. Development to perfect I think came after.

They arent spending the resorces rebuilding the country because they dont have control of it. The US is a big place.

They were created before the War. See e.g.:

http://fallout.wikia.com/wiki/AER9_Laser_Rifle

ok...i was wondering about that for awhile now,so thanks

The only people actually making new energy weapon models are the Enclave.

I think you missed the brotherhood. Vree suggests you ask the Paladins about the new laser pistol she designed...

{124}{Vree18}{Speak to the knights. Ask them to show you one of
the latest laser pistols I designed.}

Sorry, actually meant to say that the Enclave are the only ones designing new weapons superior to the pre-War ones. The Brotherhood just imitates pre-War tech, but it does not surpass it.

Dont forget the Institute. It would seem their weapons development is about as advanced as the Enclave (A3-21's Plasma Weapon)