As we stand here today, the TOP/IRON-C&G front of the Bi-Polar War has been raging for a month and a half (the entirety of February, 12 days of March and 3 of January), and for almost all of that time has been a one sided destruction of the pre-emptive attackers. Peace negotiations are taking place, but so far the only terms offered by the winners are quite outrageous, and the rhetoric from C&G is not conciliatory – for example they have called the TOP/IRON counter-offer 'insulting' and suggested that they did not highball the original offer.
The question begins to arise, how long can a war (and a defensive front of a war) be permitted to go on before it becomes oppression, extended war and all those other things used to describe Hegemonic wars? How long should C&G be able to claim the moral high ground associated with 'defence' (even though they could have avoided the front, as explained elsewhere, should they have not wished for the war) before bringing serious offers to the peace table?
On this particular issue we are short of precedents. In Karma, the NPO was kept down for just on three months – but the NPO was paying for the sins of the entire Hegemony, and a large part of that time was a waiting game attempting to goad the larger nations out of peace mode. IRON received peace after one month, Echelon a month and a half, and as part of the 'Coalition of Cowards', their entry was considered aggressive by Karma. (The rest of the CoC received peace earlier and with lighter terms.)
During the BLEU war and noCB, hostilities lasted one month in total (excluding OcUK). This conflict has also been used as precedent for peace terms, with then-record reparations being demanded, and the beginning of the end for 'draconian terms' like wonder decom and forced government changes, but today we are looking at the duration of war. Unlike in this war, the pre-empters won, but the arguments around the timing and terms of the peace were similar to today; Polaris was attacked for being a threat and peace was only offered when that was deemed to be no longer the case. This war – and the peace after – has long been used as an example of injustice, starting with the Vox Populi movement in the immediate aftermath of that war.
Previous major wars also lasted one month or less. The time for the first 'extended war' in modern history – VietFAN (part 1), described as an 'occupation-like conflict' in its official history – was three months.
FAN attacked the protectorate of a bloc member out of the blue, a significantly worse crime of aggression than a pre-emptive attack during an existing war. The CoC during Karma attacked already militarily engaged alliances during an existing war, a lesser crime of aggression. That would put the answer to the question at somewhere between one month and three for the intermediate crime of TOP/IRON. The only directly comparable precedent is that of Legion during GW3, though that war is not modern enough to be a direct guide – but Legion received a broadly comparable peace to the other League alliances, after three weeks. If directly applied now, that would mean a white peace or 1 billion reps applied several weeks ago!
In conclusion, it appears that by the only direct precedent of the treatment of pre-emptive attacks during war, C&G would already have overstepped the mark for what is reasonable (in fact kept TOP/IRON down for twice as long as Legion were). On more recent precedents, of related but not identical situations, that time is round about now. People may point to the NPO in Karma, but most alliances in Karma received peace in less time than TOP/IRON have been kept at war, and the extended duration of the NPO front was down to waiting for 'peace mode warriors' (and perhaps nascent hegemonic thoughts from Athens, who have been at the forefront of neo-hegemonist actions since C&G became strong enough to do them).
C&G should be coming to the table with the intention of actually negotiating a fair and reasonable peace settlement, not continuing with an extended, unbalanced war of occupation under the fig leaf of 'defence'.