Love a good sci fi book, the best that i have ever read is battle field earth by L Ron Hubbard.
Dont be put off by the film that was made of half of the book, that film was total crap, it even won awards for being the biggest turkey evr made in the film industry.
Honestly this book has the lot, politics, aliens, medicine, survivalist, etc. for a must read, cant put down book , read this at once