Outremer
After Louis
My essay on the Seventh Crusade covers the activities of Louis while he was in Outremer. He left in 1254 and certainly believed he was leaving behind a strengthened and orderly state. It was not so.
Internally, Outremer was no better than before. With no strong central government, quarrels broke out all most at once. The Templars and Hospitallers continued to go their own way. Worse, open war broke out among the Italians.
Externally, the Mongols pressed ever closer. This was regarded with welcome joy by the Christians, for they believed the Mongols were an enemy of Islam. Powerful fears and beliefs were at work here, leading the Christians to a series of faulty conclusions.
The Myth of Prester John
The origins of this myth are obscure and go well back into the 12th century, but by this time it was pretty clearly articulated. Somewhere away in the East was a great Christian prince known as Prester John. He commanded a vast army. Some day, Prester John would bring that great army westward, join with the crusader princes, and together they would crush Islam utterly and return all of the Holy Land to Christian rule.
As with any good myth, there were enough confirming truths to make it convincing. There were, for example, a good many Christians on the steppes of Asia, mostly belonging to the Nestorian Church. Indeed, the wife of the Great Khan himself was a Nestorian. It was well known that the Mongols repeatedly would, in the cities they captured, slaughter the Muslims while sparing the Christians. Missionaries had gone to the Mongol courts and were well received. Surely, then, the Mongols were this promised Eastern army, for it was well known that God might choose even the infidel as an instrument to do His will. You didn't have to believe every scrap of the myth to turn a hopeful eye toward the East.
This combined with a long history of disappointments in the West. It's not that the Palestinian barons gave up asking for help from Europe, but there's a definite tone—and even specific diplomatic activity—that was aimed eastward. There was never any real hope in that direction, though. Even had the Mongols conquered all the Near East, they would never have allowed the Holy Land to be independent, and the Kingdom of Jerusalem would never have submitted to a Mongol overlord. All this chimerical hope produced was good intentions wasted.