There is a fundamental dichotomy within this game which polarises players over war and it's centred around the fact that the game takes a long time to learn to play well, a long time to build an empire and a long time to reach higher levels. It's therefore natural that, when some players have spent a long time and a lot of effort growing assets, they don't want to lose them. It's also natural for some players to want to raid others and take those assets, rather than building their own slowly.
In the 'old days' there was no secured mode and few people could afford permanent war protection. Wars arose because of a genuine grudge and were less cavalier because both sides had something to lose. With the advent of secured mode, and the growing ease with which to gain GCs and stay in WP (fuelled by the changes in the game which saw the uses for GCs grow, and therefore the need for the GMs to supply more) we experienced the rise of C3 warfare, where those players who wished to raid would keep their assets in protection and fight with C3s which they were happy to lose. Other players who did not wish to play a purely econ game lost their motivation for putting-in the time because their empires could, and sometimes were, taken down and the choice became: play econ or play war, because if you don't stay in WP you can (and probably will) be raided. The space game enhances that even further because it allows players to keep a protected empire on one planet, and quickly build up a warring set of C3s on another.
War levels are the GMs' attempt to redress the balance, but putting a subroutine in place to counteract the effect of a main routine never works. If the main routine is broken, it needs to be reprogrammed.
IMHO, the 'broken' aspect of the war game is that the game needs to be reconfigured so that, if players go to war, they are both risking their assets. Sure, keep two war levels in place to protect the newbs, - one where you can attack or be attacked and one where you can't - but the game needs an element of risk to be re-associated with war. That means removing the ability to build a country quickly to be sufficiently war-capable: if you want to go to war, it needs to be with a country that has taken a long time to build to that point, and which will make you think twice about losing. That will do more to achieve the GMs' goals than their current WL initiative.
Defence and offence also need to be balanced better - the game has always favoured the aggressor. And if the GMs really want to make the war game fun to play, they will concentrate on building the tactical element - one which offers a range of attack and defence possibilities and requires both sides to really think on their feet and respond to the other's moves. At the moment, there are two or three ways in which to attack and the only variable is really distance. But that is hugely complicated and would take hellish amounts of work, both to change, and to understand.
If the GMs are set on keeping war levels, they would better serve the game, and the players, to judge those war levels on war capability - not purely on the experience a player has, but also on the weapons within their country. And I don't mean a points-based system as we have now, but a system that realistically evaluates their offensive and defensive capacity and the potential effectivity of their weapons-combination. By all means, keep the C3 WLs in place as a teaching aid - I think we can all see the advantage in that - but the PvP war game seriously needs to be re-thought.
Hugs and respect
Jo