Iraq: Saddam was a menace, had invaded a neighbor & supported international terrorism. He had chemical weapons (he used them!) and used to have a nuclear bomb program except that the IDF blew it to Kingdom Come. The long & bloody war with Iran (let them fight!) didn't slow him down at all.
So they went to "liberate Kuwait" and overthrow Saddam, but the UN chickened out & left him in power.
For Gulf II Saddam had broken the ceasefire SO many times but the UN refused to act. So the USA pulled a technicality to nullify the ceasefire, which meant that war was ON again!
After that, Bush raised a flag in Iraq and said "Here we are, come get us terrorists!" which they did. 10's of thousands of militant terrorists flooded into Iraq to die for the cause.
Imagine for a moment if those 10's of thousands had come to America instead?
9/11 once a week.

Libya: an internal struggle, a Syria-level civil war. Kaddafi had obeyed orders to remove his chemical stockpile & nuclear ambitions. The UN was monitoring the steady destruction & no violations were reported. Unlike earlier where Kaddafi had invaded neighbors? Nothing like that was happening.
Obama used an excuse of "he's going to commit atrocities if he captures an enemy-held city" to start a war without congressional approval. Kaddafi's forces did re-capture it, no atrocities, but Obama still invaded.
The war lasted longer than the (iirc) 30 day window a PotUS has before requiring Congressional approval, but Obama ignored that too.
Then Obama just... left! And the chaos that followed was far worse than the civil war had ever been! Worries about crazy Jihadists getting chemical weapons were avoided since practically all of them were destroyed already & what was left was contaminated stuff, not useful for weapons.

Afghanistan: Trump ordered the Generals to make a withdrawal plan by 2017. They didn't. He said he'd fire them if they didn't get one by 2018. They made a really shitty plan (on purpose!). He ordered them to make a working plan but then lost the election before they did.
Biden ordered the US army to "bug out". To abandon everything except for the troops & leave. Not to even destroy equipment, just leave it for the Taliban. They even gave lists of people who'd helped the US forces to the Taliban!
Some equipment was taken to neighboring nations, but many billions of $$$ went to the Taliban and has been found in the hands of Jihadi supporters globally.
It was the worst defeat in the history of the US Armed forces.

Plus there's Obama managing to lose the war in Iraq to ISIL... that's 2nd worst!
Yes, arming your enemy with billions in modern equipment is "a bad thing" ok? Letting them control a nation uncontested is bad too.