Can my bank force me to short sale my house?

My husband and I tried to do a modification, but the payments were still out of our reach. We understand we have to give up the house, but would like to avoid a foreclosure. When I contacted the bank regarding a Deed in Lieu, they informed me that I had to have the house up for sale for 3 months as a short sale and that they would demand the difference between what it sold for and what was owed, which at this time works out to be about $200k.

After reading the forum about the steps for Deed in Lieu and the other information, I have to wonder if the bank can force me to do a short sale? How can I get them to just take back the house in a Deed in Lieu. I'm saving them the trouble of foreclosure, why are they being so difficult?