That's the killing part about it. The love was there, the need for one another was there, and yet their positions, and their positions alone kept them apart. To me, they capsulized themselves up on that mountain figthing their own war. Jack was taken away, Ennis didn't know till then what he meant to Jack. What he meant to Jack, Ennis was indeed loved.
When Jack's mother put her hand on Ennis's shoulder, and invited him to go to Jack's bedroom, that was the first time he must have felt that someone understood, and taken pity on him. The shirts confirmed it all, Ennis was loved, and wanted, from that first day in '63 up until Jack's death, but his fear, living an existence void of the love and peace he had with Jack when they weren't together and insistence of long separations from his lover, clouded his understanding of what he had, this is and was the tragedy.
It didn't have to be that way. IMO.