Basically what MikeP said. Don't lie during the enlistment process. Once they find out, and the odds are much more likely they will than not, you'll have yourself a criminal record and your service will count for nothing.

The IDF Israeli Defense Force will take anyone who has a pulse might be just the place for you .

Is there a Territorial Army unit near you? Try joining the TA first. I joined the TA after I left the RAF, had a lot of fun, the pay and annual bounty isn't bad either.