ויסב אל-הים את העם דרך המדבר - Hashem took the people around through the desert (שמות יג:יח) - For a number of months before Reb Nosson finally decided to make his journey to Eretz Yisrael he deliberated about the trip for quite some time. In 5582 (1822) during the week of Parshas BeShalach Reb Nosson thought about his own circuitous journey, and felt that it was quite akin to the necessary journey of Bnei Yisrael in the desert prior to their arrival and conquest of Eretz Yisrael.
Odessa is close to Breslov, and everyday there is traffic - most of Breslov's trade is with Odessa. But, instead of going straight there I had to travel to Kaminka, Tcherin, Cherkassy, and Kremenchug until I could even get to Odessa! The Torah applies to everyone at every single moment! The reason a person has to travel a roundabout way is to increase his desire and longing. When a person wants something and it is withheld from him, he desires it even more so. The extra travel and effort increase one's desire for whatever it is one wants.
Hashem could have taken Israel straight to the land through the land of the Plishtim at the top of the Sinai peninsula. Such a route may have taken only a few weeks. But, in addition to all of the miracles, death of a generation, the reception of the Torah, and the building of the mishkan, the 40 year trip served to increase the Yidden's thirst to be in Eretz Yisrael.
And, maybe this is why our current geula is taking so long. Hashem wants us TO CRAVE the geula and LONG to go back to Eretz Yisraelin shlaymus, may it be His will soon.