Season 4 of Handmaid's Tale has already featured some brutal moments, but one of its more emotionally cutting sentiments is when June says she should've left Janine behind. June Osborne(Elisabeth Moss) has been through quite a lot already in recent episodes--ranging from recovering from her near-fatal gunshot wound to being tortured by her captors in Gilead. As usual with the series, viewers are always left wondering how much more the fiery protagonist can take from her perpetually dismal circumstances.
And this isn't the only stress June carries; she also has to deal with who she's become known as. She's seen as a resistance leader and a beacon of hope for everyone who still hasn't escaped Gilead's oppression. Mrs. Keyes is overjoyed to have June in her home not only because she becomes a sort of temporary mother/big sister figure to the girl, but also because she's become a mythologized figurehead of rebellion. Similar to how others often feel meeting June, she sees it as a chance to finally find freedom and inflict retribution on everyone who's abused her.
When June and Janine (Madeline Brewer) decide to do some train-hopping toward Chicago via stowing away in a refrigerated milk car, the stress of recent situations and underlying tensions between the two handmaids finally boils over. They have an argument, one where Janine finally asks June what's been on her mind: Whether or not she was the one who gave away the location of their safe house to the Eyes. June tells her the truth about why she had to do it to protect her daughter, but Janine insists that she wouldn't have done the same. She also voices resentment towards June for always keeping her in the dark while disclosing little information about what's actually going on. As is typical with June when she's fed up and hit a breaking point, she intensely delivers an intentionally harsh line: "I should've left you a long time ago." June apologizes (seemingly for everything that's happened during the episode) later and it's easy to see how the internal and external stress of the situation led her to snap at Janine, but there's a hint of genuineness in what she says out of anger.
In addition to trying to survive under brutal circumstances, June has become someone who means so much to so many different people in The Handmaid's Tale. She's the handmaids' fearless leader, and they listen to her commands without hesitation. Because of this, June must also see the other handmaids as baggage to an extent. She's the backbone holding it all together and being a leader can feel like a burden at times. Janine is one of the show's sweetest characters; she's likable, with a childlike innocence in many ways. But June is more of a leader and go-getter by nature. Now and again, she has to act almost act as Janine's coach, motivating her to keep moving forward throughout the course of the show.
It must be infuriating for June that Janine not only questions her decision to give up the safehouse location, even though June didn't have much of a choice, but also that Janine has the audacity to say that she wouldn't have done the same. Both June and Janine's overall distress that they hash out in the milk car is understandable and valid. But it also goes to show that June is still a mere human, one who's been facing horrifying circumstances for too long in The Handmaid's Tale. It's not surprising that, in moments like this one, turmoil boils over and cracks in her armor become more evident.