Chen enlists in the Duvdevan unit. The nickname "Nahcha" with which he arrived from home was also fixed by his teammates, and Chen quickly emerged as the fastest fighter. He displayed additional high abilities such as shooting, which brought him to the role of a sniper, navigation that placed him at the forefront of navigation, and more. Shortly after he completed the course and began participating in operational activities, the 'Second Intifada' broke out. The team worked very intensively and for a long time throughout Judea and Samaria to capture wanted men who were dangerous and armed murderers. This was a period when terrorism was rampant throughout the country, and many of the operations resulted in the thwarting of suicide attacks. On the way back to the unit after the end of the operation, the team liked to stop in Jerusalem, which Chen knew well, for a meal or a short outing. During the service, Nahcha tattooed two cherries, the unit's symbol, on his back.