IT hasn't always applied throughout world history, but the first rule of going to war is to have a clear vision of what you want to achieve, a detailed knowledge of your own and the opposition's strengths and weaknesses and, possibly most importantly of all, a firm conviction that there is no alternative.
When it comes to payment for managers, the GAA authorities appear convinced on the first and last requirements, but can't be nearly as certain on the other one. And, therein lies the risk of the Association being dragged into a messy conflict which could last for years without delivering a conclusive outcome.
GAA history shows that it nearly always has a big issue lurking in the background. For years, it was 'The Ban', the blunt instrument used to allegedly assert a sense of 'Irishness', which was deemed to be contaminated by something as peripheral as attending a function organised by a soccer or rugby club. Bizarrely, it survived until 1971, before being swept away by the reality of a rapidly changing Ireland.
Then, there was Rule 21 (the ban on British soldiers and RUC officers joining the GAA). It, too, was divisive for a long time, but gradually grew less relevant with the emerging peace process before being removed in 2001.
Next up was Rule 42 (ban on 'foreign games' being played on GAA grounds) and a controversy which had rumbled on throughout the 1990s before reaching a climax when it looked as if Ireland's rugby and soccer home internationals would have to be exported to Britain while Lansdowne Road was being redeveloped. The rule was amended in 2005, earning huge kudos for the GAA, not to mention the welcome bonus of €36m in rent money for the use of Croke Park by the IRFU and FAI for the 2007-2010 seasons.
The latest 'big issue' is payment to managers, specifically under-the-counter arrangements which are illegal under GAA rules. Simmering for the past 20 years, it has now reached boiling point, arising from Paraic Duffy's comments in March, 2010 that doing nothing was not an option, Christy's Cooney's describing it as "a cancer running through our organisation" in April 2011 and the publication of Duffy's position paper this week. Top county officers have been summoned to Croke Park today for a meeting where they will be briefed by Cooney and Duffy and invited to offer their own ideas on how the problem of illegal payments can be solved.
The message from Croke Park is clear: this has got to be tackled and resolved. After that, there's very little clarity because unlike Rules 27, 21 and 42, this is not a strict policy issue, but rather a question of how to deal with wilful violations of policy. That's where the danger arises that the GAA will be dragged into an internal battle which it can't win.
The rules on illegal payments are being broken by their own members, but, since it's impossible to prove, how can there be a solution under the current regulations?
There can't, which is why the Duffy option of tightening up monitoring and auditing procedures simply won't work. You can't monitor or audit what you can't see and if -- as extensive anecdotal evidence has it -- illegal payment is either made in cash by county boards, supporters' clubs, sponsors or private benefactors, then there's no chance of stopping it.
Another Duffy option is to pay managers officially, either on an 'invoice for services' system or employment contracts. Both come down to the same basic fact: managers would be treated differently to players. The argument in favour of that centres on the huge amount of work modern-day inter-county managers put in.
The counter argument is that they take the job of their own volition and shouldn't expect to be rewarded financially. Duffy's position paper offers no favoured solution, instead confining itself to outlining the available options, while explaining the negatives and positives attached to each of them.
A special committee will draft formal proposals later on, but this is such a complex area that it will be nothing short of remarkable if they come up with a structured solution which meets with widespread approval.
There are many who believe that managers should be paid, but if that eventually proves to be the 'solution', how long before players demand a slice of the financial action? The GPA won't make an issue of it for now, but what if a more militant generation of players emerges over the next decade, calling for financial recompense for their efforts?
Official managerial payments would make the players' case far more compelling on the basis that as the wealth generators, they should be just as entitled to payment as the man who runs the line.
Under normal circumstances, payment to managers would not be on the GAA agenda in any form. In fact, the only reason that it's such a big issue is because it has created a black economy outside the GAA's control.
Effectively, paying managers is being put forward as an option because elements within the GAA continue to break their own rules.
Now, that's one messy war to take on. Around 150 senior county officials will attend today's meeting in Croke Park, all listening intently to Cooney and Duffy and, no doubt, applauding when the rhetoric is pumped up regarding how 'illegal' payments cannot be allowed to continue.
Yet, as Cooney and Duffy look out at the audience, they'll know that many of the counties, which the officers represent, are either paying -- or allowing others to pay -- managers. As for the club scene, it's even more fertile territory for brown envelopes.
Still, Duffy and Cooney have now put the GAA on a war footing. The days of diplomacy are over and instead the strategy for battle is being prepared. However, this is a war not against 'outsiders,' but rather against the failure of the GAA's own members to adhere to a policy which they profess to support.
In a sense, it's a civil war and history shows just how destructive that can be.