Conor revealed that earlier this year, following desperate pleas for help from Ukrainian forces, he "moved" and enlisted in the Ukrainian International Legion — a branch designated for international volunteers.
When revealing his decision to enlist and serve on the front lines, he simply said, "I wanted to help."
In an Instagram post by Conor, he briefly shared his experience, not revealing where or when exactly his combat mission took place or why he returned to the United States.
"I know this story is coming out, so I want to say my piece first to make the best of it and encourage others to take action," the caption read. "Like many people, I was deeply moved by what I saw happening in Ukraine over the past year."
"I wanted to help," Conor continued. "When I heard about Ukraine's International Legion, I knew I was going."
Conor said that after finding out about the international volunteer branch, he paid a visit to the embassy "to enlist the next day."
The Kennedy grandson went to great lengths to keep his family's name — and his status — under wraps.
"I told one person here where I was, and I told one person there my real name," Conor disclosed.
Conor's sister, Kyra, commented her support on the post, while Conor's girlfriend, Brazilian singer Giulia B, praised his efforts and courageousness.
"You're the bravest man I've ever known, my love," Giulia B's comment read. "Being away from you and worrying for all those months was incredibly hard, but we kept our faith all the way through."
On why he chose to keep his identity a secret, Conor also provided his reasoning.
"I didn't want my family or friends to worry, and I didn't want to be treated differently there," Conor revealed about why he kept a tight lip on his background and plans.
Conor also revealed that he was not "a great shot" but due to his willingness to help and ability to "carry heavy things and learned fast," he earned his place on the northeastern front.
Without glamorizing it, Conor also made the shocking revelation that he was "willing to die there."
The 28-year-old opted to keep some parts of his service to himself, adding, "My friends there know why I had to come home."
Conor summed up his experience by stating that, "My time in Ukraine wasn't long but I saw a lot and felt a lot. I liked being a soldier, more than I had expected. It is scary. But life is simple, and the rewards for finding courage and doing good are substantial."