If you aren't being sarcastic...
The elves have already been fighting against Morgoth and his minions for eons. Their numbers and energy are mostly spent by the time of the War of the Ring. Very few were left after the end of the first age, and those dwindled over the course of the second and third ages. Factor in ancient mistrust and general isolationism... Anyway, the short answer is there aren't enough of them left, and they're totally burnt out from fightin' all those bad guys for so damn long.
The dwarves are essentially decimated during various wars with orcs before we ever get to the War of the Ring. Like the elves, there aren't many left, they have little cultural ambition, and are very isolationist. However, the dwarves did play more of a factor then is readily apparent (esp. in the movies). In "The Hobbit" the dwarves retake Lonely Mountain and garrison it with troops from their strong settlements to the north. During the War of the Ring, these dwarves maintained a northeastern front against Sauron's forces coming around to descend on Rohan- instead, it is only Saruman who is able to attack Rohan in force. I think it's mentioned in the books, perhaps in an apendix- been a long time since I read them fully.
Hobbits...well, hobbits are just fat. And short.
/complete fucking nerd mode off