The late Fr. Thomas Hopko once read a paper he presented at a symposium called by Rome to learn what other churches would need to see in order to accept the papacy. You can find this in his Speaking Truth in Love podcast.
At certain point in podcast he drills into the divine energies as one of the prerequisites. This goes all the way back to the controversies surrounding the reaction to Palamas in the West, a topic far too complex to elicit much desire on my end to recount it here.
Rather, I would prefer to focus on what the impressions of this very particular requirement from the perspective of a Catholic turned Orthodox. In short: Really? Really? Of all the items out there genuinely blocking reunion, the energies are it?
One of the problems faced by ecclesiastics and theologians (even the good ones) is the tendency to loose sight of the practical, pragmatic, obvious, and just plainly real, getting lost in minutiae of theological distinctions...in this case between two churches that hold an outrageous amount as common confession of faith.
Without intellectual acrobatics, find me the divine energies in the earliest, pre-schism creeds and canons? This isn't to say I don't believe Palamas. It is to ask, however: really, and I mean really, how much of a tangible difference can you identify between communicants of the Orthodox Church vs those of the Catholic Church due to the issue of the divine energies?
Go on. Do it. Find me the example of the average Orthodox in canonically good standing who would even know what the divine energies are, let alone how their life is any different from observant and orthodox Catholics. When you do, I'll be all ears.
The reality is that the reunion between Rome and the Orthodox Patriarchates hinges upon much more blunt and obvious issues than the divine energies and who governs Vatican City, and other such seemingly esoteric points.
Practically speaking, in the real world, in the life of faithful Orthodox and faithful Catholic these are the 2 issues that Rome would need to "come home on" from and Orthodox perspective:
1) Papal Infallibility - numero uno, easy number one, and the ultimate cause of the following 3 issues. The Orthodox maintain that there is no evidence to support universal jurisdiction and authority over other Patriarchs. It is an issue that would undoubtedly have serious ramifications for the Roman Church, as the Pope has a central place in its ecclesiastical life.
2) The Immaculate Conception - Another "dogma of the faith" that the Orthodox Church contends needs to go. It is nearly impossible to demonstrate from either Scripture or the earliest tradition and is ultimately grounded on a bad translation of Romans (Vulgate). At best, it is superfluous. At worst, it propagates a questionable reading of the fall via Augustine's concept of original sin. Given the devotional life built up around the Immaculate Conception and its now central place in the Marian cultus, this would again result in massive ramifications for the Roman Church.
3) The old Fessiwig...I mean Filioque. I don't mean to be so nonchalant about it, but it is what it is. The old stand by issue. In virtue of its antiquity, this is one that just won't be let go....although, if reports from Calabria are to be believed, the disagreement over the Filioque, generating as it did centuries after the addition, failed to prove the source of any tangible friction between Latin and Greek churches in Southern Italy. Truth be told, the evidence seems to indicate they both carried on like the schism didn't exist. In virtue of the antiquity of this disagreement, you've got to include it....but one does seriously have ask if it produces any tangible distinction between Catholic and Orthodox.
Outside of these three issues (maybe 2 if I'm honest with myself), the points of separation are largely obscure, esoteric, and leave little practical impact on the majority of the faithful. Now, I could be wrong here - there could indeed but other very practical items I'm missing, but this really seems to be it.
Reunion remains a long way off. It was once common to accept the idea that aggressive secularization and Islamic growth are pressures shared by all Christian churches, and these two pressures would ultimately force unification in order to have a credible and impactful response...in reality, there is nothing to suggest that the pressures from even these dominant trends are pressuring either church to take a more practical approach to reunion. In point of fact, it seems that a hardening of boundary lines appears to be underway in some quarters.
To reveal my hand here, I am largely familiar with this among Roman Catholic circles. The aggressive secularization and the orientation of the current papacy to it has resulted in Traditionalist groups getting more hardline in their approach to the Orthodox Church. It seems the Orthodox Church is increasingly seen as a threat, in so far as occasionally people leave Rome for one of the Orthodox Patriarchates. Largely, I think this is psychological on the part of the people writing about it. Frankly, not many Catholics are leaving to become Orthodox. As such, I tend to think their missives and warnings about not jumping to the Orthodox Church reflect their own internal desire and struggle with the thought - the practical activity just doesn't give any credence to this being a phenomenon in any appreciable sense. The Orthodox Church is also seen as a threat when it comes to discussions of priestly celibacy - it is feared, justly or not, that the fact of non-mandatory celibacy in the Orthodox Church is going to be used a trojan horse to not only institute optional celibacy, but also a host of other surprises lurking around the corners in the dark alleys of the Traddie internet. I'll let you decide if that is a reasonable fear or not...
In any case, it is reasonable to ask "what does Rome have to do?" Rome has asked that same question for a while (although, I fear Rome will cease asking the question if the next Pope is a reaction to Pope Francis). In my estimation, the substantial points of confluence and agreement far out number and out weigh the points of disagreement. The Orthodox Church can't have its cake and eat it too on this one - nor should we want to! If Rome were to dropkick the whole idea of papal infallibility and universal jurisdiction, then it would make sense just to roll with it, frankly. Most of the other distinctions that have been a source of sore exchange existed well before the schism in one way or another and were never thought of as impinging upon the unity of faith.