Date: Erev 13 Teves 5560
From: Rabbi Moshe Sofer
To: Rabbi David
The Chasam Sofer rules that a man who breaks his engagement may be compelled by the authorities to proceed with marriage, and the resulting kiddushin is valid. This is established on two grounds: the cherem and monetary penalties he accepted at the time of the engagement make the marriage his atonement—analogous to coercing one to bring a korban until he declares willingness—and the man's own recitation of the kiddushin formula constitutes the required consent. Nevertheless, if genuine marital discord is certain, separation is preferable.
Source: Shu"t Chasam Sofer EH I §112