In my opinion, there is no such thing as being safe without supplemental brakes, but lots of folks do and say they never have had a problem. I've flat towed a Jeep Wrangler of one sort or another over 100,000 miles over the years, and I know my supplemental brakes have saved the day numerous times... the latest being yesterday in downtown Las Vegas on our way home from Colorado. Additionally, your Dodge owners manual may actually specify the necessity of brakes on a towed vehicle over a specific weight.
Read this first, then decide if you are willing to assume the risk of towing without a supplemental brake system...
The Physics of Towed Vehicles