At approximately 2:20 pm arizona time on 2/21/2018 i witnessed the following event. two fighter jets that appeared to be f-15's flying at about 10k-15k feet approached lake havasu city from due west. i am not a military jet expert and can not definitively identify their models. both jets left double-wide contrails. although they both left contrails, there were maybe a dozen instances where they stopped leaving contrails for a few seconds, or left contrails in "morse code"-like patterns before steady contrails resumed. both jets had swept wings. they made some very unusual sharp turns which caused me to notice and observe them. they zig-zagged in unison over a wide swath over the area for about 10 minutes, then flew back in the direction from which they came. there was something up there with them. it was a long white object. compared to the jets, it was maybe 3 to 4 times as long and from my vantage point seemed to be about as wide as the fuselage. it did not leave a contrail. the jets appeared to chasing it. i only saw the white object briefly. i didn't notice it until well into the event at which point it was about 60 degrees above the horizon north east of my vantage point. i watched it for about 15-20 seconds then knocked on our front door to get the wife to come out and see it. when i looked back in the sky i had lost track of it. the jets continued to zig-zag across the sky for maybe 5 more minutes before flying in a straight line back in the direction from which they came. while the jets were making their departure i talked to one of my neighbors who also observed the event, but she did not see the white object.