How can you think any of these problems can be solved by intelligence when none of them have been solved?

War has already been solved to some extent by intelligence (negotiations and diplomacy significantly decreased instances of war), hunger has been solved in large chunks of the world by intelligence, energy limits have been solved several times by intelligence, resource shortages ditto, intelligence has made a good first attempt at space travel (the moon is quite far away), and intelligence has made huge bounds towards solving the problem of loss of loved ones (vaccination, medical intervention, surgery, lifespans in the high 70s, etc).

Many wars are due to ideological priorities.

This is a constraint satisfaction problem (give as many ideologies as much of what they want as possible). Intelligence solves those problems.