"that's only around 2500, and that's not enough for a war"
I didn't know there was a minimum buy-in at this poker table.
Here's the thing: we don't need to kill every last one of the al-Qaeda rebels in Mali. Just enough of them that the locals can do the rest, or chase them away. That doesn't involve US support, other than maybe some random "unattributed explosions" (read: Reaper strikes against selected targets). The Tuaregs are supposedly not happy with aQ already, and the other forces (specifically the ECOWAS nations) are more than capable of routing them. And there will be more US involvement (we've already had SF guys on the ground there, a few were killed in a car accident in the last year or so), but it won't be a significant force, and it will be highly "advisor/support" in role.
Is that a long-term answer? No. But it might be enought to do the job for awhile.
Active-duty US Navy