Reading newspaper reports, my impression has been that what caused Hatoyama to change his mind at the last moment was opposition within his own group in the Diet to the non-confidence vote, at least under the present circumstances. Another possible factor blocking the non-confidence vote had been Kan's indication that he might dissolve the HR and call for elections - sort of a modern version of Samson and the Philistines (whether all Kan's zouhan are familiar with the Biblical story is irrelevant).

FWIW.

Ehud