There are two reasons I can think of for why he might have intended to purposely hand those documents over to enemy states—particularly those he doesn't even like. One is that he planned it to be a "set the place on fire on his way out" kind of move after running out of options for staying in office. You know, travel to an enemy state, hand them the secret to destroying us in exchange for letting him live there in luxury for the rest of his life, then sit back and watch the fireworks. If that is what he was up to, then clearly he failed in his mission or those fireworks would have happened by now. I'm just picturing him going around from country to country, pitching his scheme to one leader after another, only to get repeatedly turned down and walking away frustrated.
The other possibility is that he's holding onto it with plans to do that later. Either as a form of blackmail—"Make me President again or I will send this information to our enemies"—or a revenge plan for after his next campaign fails.
...Good lord, it just hit me that we're discussing a former US President like we're analyzing the motivations of a comic-book villain.