Go with the security system regardless - use it in stay mode when you're home too. If you've got a smash and grab/meth problem anyway it could buy you an extra second or so while the dogs get oriented to the threat. Depending on your real estate market, you'll get most or more of the costs back when you re-sell for the next PCS anyway.
If you haven't yet, file a police report to get a legal record going, and next time(s) you arrive and think you've been breached, let them clear it, building clearance might have been our ('91 ODS, '04-'05 OIF, '11 OND in my case) deal in OIF/OEF, but you can get legal-slammed for "perp-hunting" in a lot of states (PTSD driven babykiller, etc...), even if you eventually win the case, it will be expensive. Additionally, you could be "tampering" with a crime scene and hinder future criminal prosecution.
As far as the stock NRA Refuse To Be a Victim answer, "Back out, go to a safe location, call 911, and wait for the police."