I agree with No. 1. But he did not create the underlying conditions for it. If you want to take a partisan approach, Clinton could have had Bin Laden long before, but declined.
2. Bush the Elder and Saddam Hussein got us into the first phase of the Iraq War, which ended with a truce that was repeatedly broken by Saddam Hussein. Bush the Younger, the U.S. Congress and virtually every foreign intelligence agency, as well as Saddam’s shooting at U.S. and Brit planes in violation of the truce, got us into the second phase of the war.
3. While no attack has been as deadly as 911 since then, there have certainly been attacks. One needs to remember that the security apparatus under Obama was set up by Bush.
4. So, one Islamic radical leader was killed? Exactly how has that prevented the rise of ISIS, the takeover of Aden by A.Q., the Islamist takeover of much of North Africa and the flight of refugees from those areas? Manifestly, it did none of those things.
Without any pretense to legal skills, I would nevertheless at this point move for Summary Judgment inasmuch as your four points have neither proved a case against Bush or for Obama, even if the facts asserted are true, (which is not conceded) in the matter of the refugee crisis afflicting Europe and the refugees themselves.
For #2, I did use the term “protracted” war and, further, Obama voted against it in the Senate in the first place. And for #3, you know for a fact the nation’s defense was not modified in any way for the better by Obama?
Since a full counter-rebuttal would take us too far from the OP, the court is adjourned for the day.