Here is a thought experiment. Let’s imagine that the US invasion of Iraq was managed on the same level as the Russian 
invasion of Ukraine.

Day 1

20 of March 2003, 05:33
US forces start a special military operation in Iraq.

Day 2
US, Ali Al Salem Air Base in Kuwait is under Iraqi rocket shelling; some airplanes are destroyed 

Day 3
A Ministry of Defense spokesman announces that the Iraqi Air Force is now completely annihilated.

Day 4
US forces claimed to enter Fallujah

Day 8
Dozens of videos of Iraqi trucks towing M1A2 Abrams and M2 Bradley vehicles near Bahdad Independent sources confirm at least 200 tanks were lost by the US forces.

Day 24
Iraqi helicopters attack a US Army fuel storage base in Kuwait.

Day 30
US forces and Allies retreat from Mosul to Turkish territory.

Day 42
Iraqi armed forces manage to sink the 6th fleet flagman ship, the USS Mount Whitney.

Day 54
Fallujah is claimed to be controlled by the allied forces 

Day 67
Independent sources confirm at least 2,000 armored vehicles lost by the US forces. Reactivated M48 Patton tanks are spotted near Basra.

Day 70
Iraq’s flea markets are booming. You can find US Special Forces equipment and weapons. Unfortunately, the price bites 

Day 80
In a single day, US forces lose five F-16 planes and four AH-64 Apache helicopters.

Day 98
Failure of US diplomacy: the Iraqi Army receives powerful MLRS from its allies. TV channels across the world air videos of detonating US munition storage bases 

Day 112
Fallujah is claimed to be controlled by the allied forces 

Day 124
A video leaked from San Quentin State Prison: Dick Cheney is agitating prisoners to join PMC Blackwater and gain freedom after storming Fallujah.

Day 145
US forces decide to regroup their forces in Basra and take them into Kuwait.

Day 165
Tourists in Catania observe massive explosions and smoke coming from NAS Sigonella. The nature of the explosion is unclear, but US officials agree it was an accident.

Day 177
POTUS announces partial mobilization in the United States.

Day 184
Breaking news: The Golden Gate Bridge in San Francisco is partially damaged due to an explosion 

Day 190
Mobilized soldiers make videos with their issued weapons. These turn out to be rusty M16A1 rifles with broken parts. Videos go viral across the world.

Day 201
Saddam’s Army enters Kuwait… George W. Bush gives a speech about how Special Military Operations in Iraq goes according to plan 

Day 210
Two hundred members of the Republican Guard, including officers, who were taken as prisoners in Fallujah were released from Guantanamo prison. Some Syrian civilians previously sentenced to death were also released.

Day 212
Iraqi officials release information about the recent POW exchange: to free 200 Republican Guards, they had to release some Iraqi businessmen with strong ties to George W. Bush (I can’t find a reasonable real life comparison for this disgrace)

Day 220
More videos from US mobilized soldiers They are complaining about how they were left to live in the woods or abandoned buildings with no heating or other basic necessities.

Day 235
Independent sources manage to confirm 1400 US officers KIA in Iraq.

Day 240
US Supreme Court finally settles the fact that 17 seamen died at USS Mount Whitney 

Day 236
Altus Air Force Base was infiltrated by saboteurs. Two AH-64 helicopters were destroyed.

Day 249 
The Crete Naval Base is under attack by an unknown force. Some US ships are damaged. The US government points fingers at Saudi Arabia

Day 250
Independent sources can now visually confirm the loss of half of the US tanks that were in active service before the invasion

Day 255
Mobilized US soldiers strike as they do not receive promised salaries

In reality, the US invasion of Iraq was one of the best performed attacks in history to date. 
The Iraqi Army was very similar to the Army of Ukraine: 375,000 personnel on active duty and 650,000 reservists armed with 5700 trucked and wheeled vehicles (mostly Soviet-made, just like in Ukraine).

The initial part of the war lasted just over a month and was a complete success, with coalition casualties totaling 196 people.