Krim refused to use the militia to put down civil unrest on Bajor, believing that it would lead to civil war. In reality, he was a member of the Circle, who wanted the Federation to leave the Bajoran sector. Krim led a siege on Deep Space 9 in 2370, but ultimately surrendered the station back to the Federation after meeting with Li Nalas and discovering that the Circle was backed by the Cardassians. He expected the Bajoran Provisional Government would ask for his resignation.
Although Krim was on the opposing side, he appeared to have a respect for his adversary, Benjamin Sisko, noting during their meeting that Sisko gave him information rather than use it as a bargaining chip. He had first met Sisko at a session of the Bajoran Executive Committee in 2369. In the later takeover of Deep Space 9, he was pleased to discover that Sisko had not abandoned his post, as it increased his esteem for the commander. (DS9: "The Circle", "The Siege")
"You can't possibly appreciate that this is Bajoran against Bajoran."
"I can appreciate that the provisional government will stand only if the military supports it."
"We are all patriots, Commander."
"Commander Sisko, you told me about the Kressari before you asked the favour regarding Kira. You could've tried to trade that information for the favour."
"I wouldn't do that."
"I'll remember that about you."
"You're be playing right into their hands."
"If you're so convinced they're still here, how can you sit and wait for them to attack?"
"They have no interest in attacking."
"What makes you so sure?"
"Because I understand military tactics."
"I'm returning to the surface immediately to consult with the Ministers. I expect I will be asked to resign. Commander, since the provisional government has prevailed, I believe it is appropriate to return the command of this station to Starfleet. Well fought, sir."
Krim was played by actor Stephen Macht, who had previously been considered for the roles of Will Decker in Star Trek: The Motion Picture and both Jean-Luc Picard and William Riker in Star Trek: The Next Generation. (The Making of Star Trek: The Motion Picture, p. 104; Star Trek Encyclopedia; The Fifty-Year Mission: The Next 25 Years)
The script of the "The Circle" describes Krim as "a solid, handsome 50's male with a demeanor of straightforward intelligence [...] he is not a politician but a soldier and when he chooses his side, it must be the winner."  The script of "The Siege" additionally describes him as being, "purely a professional military man, a Rommel, not interested in politics". 
In his review of "The Circle", Star Trek author Keith R.A. DeCandido writes, "Stephen Macht shows tremendous gravitas as Krim, setting up his larger role in the following episode." For "The Siege", he describes Krim as being, "a worthy adversary for Sisko."  
The Worlds of Star Trek: Deep Space Nine short story "Fragments and Omens" gives Krim's full name as Krim Aldos. He is revealed to be the ex-husband of the new First Minister of Bajor, Asarem Wadeen, and to have spent the time between the "Circle" trilogy and the story (which is set in late-2376) in seclusion, though a legal commission did not find him liable for the attempted coup. First Minister Asarem asks him to serve as Bajor's Federation Councilor after her first choice dies unexpectedly, and he reluctantly assumes the office.
In Articles of the Federation, Federation President Nanietta Bacco nominates Krim to the Federation Security Council to replace Artrin na Yel, who had recently been forced to resign. Krim is appointed that same day after he gives a speech before the full Council responding to Councillor Bera chim Gleer of the United Planets of Tellar.
In the Star Trek: Typhon Pact novel Raise the Dawn, Krim pushes the Federation Council to approve the construction of a new space station in the Bajoran system, following the destruction of Deep Space 9 by the Typhon Pact in 2383.
Krim also appears in the Star Trek Customizable Card Game which describes him as a "thoughtful tactician" and names him as the commander of the Bajoran vessel Talnot.