Complex sentence: Bond is sent to make sure that Le Chiffre does not win back the money; the reasoning is to force Le Chiffre to turn to MI6 for protection, in exchange for information on his creditors and employers.
Split into simpler sentences: Bond is sent to make sure that Le Chiffre does not win back the money. The reasoning is to force Le Chiffre to turn to MI6 for protection, in exchange for information on his creditors and employers.