International football is a battlefield when it comes to recruitment of players.
And despite a complaint from Michael O'Neill about the FAI's policy of recruiting players from north of the border, Martin O'Neill has no plans to hold back in the chase for talent.
If a player is eligible to play for the Republic of Ireland, and wants to play, then the FAI will exercise their rights to pick the player: that was the clear message from Martin O'Neill.
"The player has the choice. I think that is very important and something that's been overlooked in this," said a serious-looking Martin O'Neill.
"They're not being coerced into doing this here. They're being asked. And if I was a player and two nations were looking for me, I think that I'd be kind of overjoyed about that."
The Republic's boss was in Dublin yesterday on official business, naming a 30-man squad for a training camp and friendly in Turkey in two weeks' time, though only 25 will travel to Antalya on Monday week.
There were a few talking points: the omission of senior players like Darren Randolph, Stephen Ward and Richard Keogh (still very much part of the plans but excused this time) as well as possible retirements.
There are also uncapped players (eight) and others keen to use the Turkey game to add to caps already won (John Egan, Alan Browme, Alan Judge, Greg Cunningham).
But it was the issue of cross-border traffic which dominated the agenda for O'Neill, who was asked to respond to weekend comments by his namesake and counterpart with Northern Ireland.
An online version of an interview with Michael O'Neill used the word "weasel" in relation to the FAI (though not Martin O'Neill personally) and was the first expression of anger from Michael O'Neill, who is clearly frustrated that northern-born footballers end up in the green shirt of the Republic.
A subsequent, printed, version of that interview had that contentious word removed.
There's no doubt that Michael's comments wounded Martin and it's likely that the relationship between the two men has cooled: Martin would not confirm if his counterpart had apologised.
"I think you'll have to speak to Michael," he said about an apology. "I'm disappointed with the comments, and the way they were made.
"I think the choice of words, particular the initial on-line words, became a bit of a problem. My relationship with Michael is very good, excellent. He's done an excellent job with Irish squad in the last four years. I'm disappointed with the comments, disappointed if they were even remotely aimed at me, not true.
"He mentioned a player I didn't know anything about, pure supposition about a player in the case of (Paddy) McNair, that he was mentioned as a Catholic or a Protestant, that we didn't bother pursuing it. I'd no idea. My association would say that's it's absolutely and utterly untrue."
Martin O'Neill made the point, more than once, that international allegiance is in a state of flux. He mentioned a player now on the books of Barcelona B (Marcus McGuane) who played competitively for the Republic at U17 level but is now with his native England, as well as the Jack Grealish saga.
And there are also players who try and serve two masters at the same time: The Herald asked O'Neill about the case of Rangers striker Matthew Shiels who played for the U19 side with the Republic (against Romania) and Scotland (against Denmark) in the space of 14 days last month.
Martin concedes that eligibility rules backed up by the Good Friday Agreement, where any player born on the island can declare for the Republic even without the "blood link" mentioned by Michael O'Neill, may be unfair on the IFA.
"I can't see how that can be of any benefit to Northern Ireland," he said, but he also stands by his own record where no player has crossed over at senior level in Martin's time as Republic boss.
"In terms of senior football, he (Michael) had to admit the other day in the conversation that I've never taken a player from him. Not one player," he said.