We'd watch an entire show based around President Logan. The character is fascinating, as he brought the Russians back to the table this week by blackmailing them with evidence that he could prove they were behind Hassan's murder. Complete BS? We don't know. He wouldn't reveal any sources.
Logan was in a celebratory mood when he returned to the UN because he was relevant again, helping his country. But he soon learned, from his shady assistant's contact, that Jack Bauer was on his way to CTU to interrogate Dana Walsh. Why? Because Sergei told Jack earlier that Moscow was behind the events of the day and Dana knew all about it. At this, Logan flipped out. He said Bauer's involvement might expose the Russian plans (and maybe implicate Logan somehow?) and ruin Logan's triumph.
He went into the UN and made his case to President Taylor. He told her all about the Russians, but also that the peace treaty had to be signed. She had to look at the bigger picture and not allow Jack to fully interrogate Dana. It created a nice moral dilemma for Taylor, who eventually sided with Logan.
She actually went to CTU and sat Jack down. She tried to explain to him that the peace treaty was too important. Even if the Russians were behind the events of the day, they were back at the table and peace was more urgent than revenge.
Jack said he didn't care about revenge for Renee. He wanted justice. But Taylor refused to give Dana immunity in exchange for her information and even ordered Jack onto a chopper to be debriefed elsewhere.
As Jack made his way to the CTU tarmac, though, he grabbed the gun of a fellow agent and commandeered the helicopter. Not even Chloe could talk him out of it, as she had a job to do as the new head of CTU: she called in the airforce to force down this rogue chopper. We cut to black with Jack flying over the sky of NYC. Destination unknown.