In Virat Kohli’s defence, there is a line that must not be crossed while sledging. It should never descend into outright abuse and verbal assault. One can only assume that Kohli feels this line was crossed.

“Is it too late to say I'm sorry now?” Lyrics from Justin Bieber’s smash hit ‘Sorry’ seem strangely appropriate for the final act of the Border-Gavaskar series. This was probably the thought running through the head of Australian captain Steve Smith at the end of a hard-fought, fiery, and at times ill-tempered series against India.

The battle for the Border-Gavaskar Trophy has often been a heated one over the last two decades, ever since Sourav Ganguly dared to stand up to Steve Waugh’s mighty, record-breaking Australians.

Ganguly started India on the path to countering ‘mental disintegration’ with his own brand of gamesmanship and verbal assaults. Since then, the battles between these two rivals have more often than not been fought in a tense and hostile atmosphere with tempers at boiling point.

The 2017 edition of this now epic rivalry was no different, with several dramas and incidents blighting the contest and often detracting from the riveting cricket on display. As in the past, much of the focus surrounded the two captains.

Smith, in the form of his life, and Kohli, arguably in the worst form of his, were at the center of almost every controversy that engulfed the series. From Smith’s ‘brain fade’ to Kohli’s accusation that use of the dressing room for Decision Review System (DRS) assistance was more than just an honest, one-off mistake, through to Glenn Maxwell’s mocking of Kohli’s shoulder injury and Smith allegedly calling Murali Vijay a ****ing cheat on live television.

While Smith has apologised and appears willing to forgive and forget, his opposite number does not share the same diplomatic view of the situation.

Before the series began, Kohli spoke of the sledging and verbals that players on both sides would expect during the Test series, and how despite the heated nature of matches between the countries he maintained good relationships and even friendships with many of his Australian foes. It seemed he was a firm believer in what happens on the field stays on the field.

However, it didn’t take long for any notions of friendship, and any misplaced ideas that this might be a series played in a friendly and jovial atmosphere, to go out the window. The cricket was aggressive and intense, with drama to match.

Much of it was sparked by ‘DRS Gate’ and Smith’s supposed brain fade in Bengaluru. Post match, Smith apologised and admitted his mistake. His counterpart, however, believed this was no brain fade, but merely the first time the Australians had been caught in a larger more devious plot to rort the DRS.

It’s fair to say the Australians — players, fans, and media, didn’t take kindly to Kohli’s accusations.

The animosity between the sides grew in the third Test when Maxwell mocked Kohli’s shoulder injury after diving for a ball in the field in a similar manner to the incident which caused the Indian captain’s injury.

Then, in one of the final acts of the series decider at Dharamsala, Vijay claimed a catch which on replay was deemed to have hit the turf, and therefore the out decision was overturned.

After the replay Smith was supposedly caught in the dressing room calling his opponent a cheat. This was the final straw.

These incidents, combined with a constant verbal barrage from both sides such as the now infamous tit for tat between Matt Wade, Smith and Ravindra Jadeja, drove a massive wedge between the teams as they tried to gain an upper hand in the contest.

After the fourth Test was completed and India had reclaimed the Border-Gavaskar Trophy the two captains handled the situation in two contrasting styles in their post-match interviews and press conferences. Smith, humbled by defeat despite displaying wonderful batsmanship and skill on his part, and calmed by the contests’ end, apologised for crossing the line.

Kohli, whose series with the bat was as poor as Smith’s was good, perhaps buoyed by victory stubbornly chose to give one final spray to his opponents by declaring those friendships he had spoken of pre-series were now over.

Both men were well within their rights to say what they did. Smith, clearly regretted his own actions and that of his teammates, and was willing to build bridges. Kohli was in no mood to accept the olive branch, and what was said on the field clearly incensed him to the point where he believed it had caused irreparable damage between the two teams.

In Kohli’s defence, there is a line that must not be crossed. Sledging, while unnecessary, should remain funny and serve as good-natured banter used to distract an opponent. It should never descend into outright abuse and verbal assault. One can only assume that Kohli feels this line was crossed, therefore he no longer wants to maintain friendships with players whose boundaries differ from his.

Smith’s apology was commendable and says a lot about him as a man and a leader of his country. One can only hope that in time both sides will see the error of their ways, but for now Kohli’s answer to Bieber, and Smith, is clear.

It’s too late to say sorry now.