The Walking Dead: Dary Dixon's second season came with as many twists and turns as one would expect. Between fights with the undead and the living who help make the hellish landscape of the post-apocalypse, Daryl learned some surprising information about another country very near to France. After encountering some Scottish survivors known as Angus and Fiona, Daryl learned that unlike most of the world, the United Kingdom's government actually managed to survive the initial outbreak of the Wildfire Virus, though it came with some heavy costs all the same. To fans' current knowledge, this makes the UK one of the only pre-apocalypse governments that are still functioning and likely has a better handle on its territory than anywhere else.
However, as with any post-apocalypse scenario, there were significant alterations to the structure of the UK's governance. It is unknown exactly what shape the country is in now, nor is it certain who is in charge anymore. That being said, there is plenty to suggest that as larger territories of survivors go, the United Kingdom might have the closest thing resembling an old world society and perhaps could be better protected against the threat of the walkers. Since Daryl and Carol are both bound for England as they attempt to return home, it would be best to try and get a handle on what they might be walking into.
The Fate of the United Kingdom
According to Angus and Fiona, the British military "locked down" the island in the first few days of the outbreak, declaring martial law in order to prevent their civilization from falling apart. As brutal as this sounds, it actually succeeded. From everything Angus and Fiona said, the United Kingdom is still functioning today. However, the Wildfire Virus outbreak was not a problem that could be solved by simply forcing civilians to remain in their homes. There was likely a lot of violence in those early years as the military sought to stabilize the situation, and some parts of England were left "desolate" by the military, suggesting there were periods of intense bombing.
The United Kingdom's military declared martial law, securing the government from falling to the walkers.
It is unknown what the leadership of the current United Kingdom looks like at this stage. While previously they had elected officials and a constitutional monarchy to follow, a military declaration of martial law could easily be another word for "coup" that used the outbreak as a pretext to restructure the government how they saw fit. It is entirely possible that the former heads of state for the United Kingdom are no longer in existence; instead, they are headed by military officials who are keeping a tight leash on the people to prevent further collapse. Whether this means the former leadership of the UK died in the initial outbreak, or something more sinister occurred has yet to be revealed.
Another aspect of the current United Kingdom is that they still possess boats that can travel worldwide. One such ship is known to have headed as far as Canada, suggesting that England maintained some contact with countries that were once loyal to the United Kingdom. Whether their relationship remained the same in the aftermath is unknown, but it seems to be implied that the trips are regular, possibly being a way to communicate new information and attempt to reestablish order or at least to trade valuable supplies. Daryl and Carol seem to be under the impression that it happens enough to be a way for them to return to America if they can find one. From everything that's been said thus far, England seems to have maintained a level of stability that other countries simply could not.
How the English Government Likely Survived
Now comes the question about how the British military accomplished what so many other countries failed to do. The easiest explanation comes from the territory they were trying to secure. England, though it is a large landmass, is ultimately an island. The chief advantage the military had here was that they didn't have to worry about other countries' problems encroaching on their territory. Nor did they have such a massive amount of territory to cover. In fact, the only part of their country that exposed them to this potential vulnerability was the Chunnel, a real-life tunnel system running beneath the English Channel that connects England to France. The British military took this into account and spent the first few years of the Trials securing the Chunnel to prevent any excess of refugees and potential further infection. There was some small degree of national solidarity, though, with British citizens who were outside the country at the time of the outbreak being allowed to return through the Chunnel to reach their people.
Only having to secure the British Isles made it easier to keep control over the country.
The next factor to take into account is their response time. The British military was said to have locked down the country almost immediately after news of the outbreak reached them. This quick reaction time likely saved many lives as the military began securing population centers to prevent the apocalyptic virus from spreading out of control. Now granted, there is nothing they could have done about it becoming airborne, but moving quickly and having a plan to slow down further infections and preventing the dead from outnumbering the living likely contributed to their current state of survival.
It's also possible that in their bid to try and keep the country from falling apart, they either imprisoned or outright executed heads of state who would otherwise have nothing to contribute to the situation beyond words that would either calm or incite panic in the general public. Given how the current situation was described as relatively stable, it is hard to imagine that they went this far, though, as there would likely have been resentment from the civilian population in the years that followed for essentially trading their liberty for safety. In an ironic twist for the world of The Walking Dead, the military going beyond its jurisdiction and declaring martial law actually worked. Again, this is likely due to the smaller territory they had to secure rather than such a plan being the correct course of action every other time, as so many other fallen governments can attest to.
England's Military Power Has Likely Been Diminished
There was a cost to this, though. England has had to close itself off from the rest of the world to survive. While it's been confirmed that they have reached out to Canada, this is only an olive branch extended to a territory they are familiar with and one that would likely welcome their presence without too much hostility. The rest of the world doesn't even seem aware that the United Kingdom's government has survived. This actually leads to the troubling implication that they may have plans for future expansion. England has always had an imperialist history, and there's no reason to rule out the possibility that they have similar designs now, given that they may very well be one of the only stable governments left in the world with a formal military to support it. It's just a question of numbers and ammunition that might be stopping them.
There were likely severe costs to declaring martial law, leaving the military weaker than it once was.
As easy as it may have sounded to say they secured the country in the first days of the apocalypse, the military likely took severe losses in their attempt to establish order. Parts of the country were destroyed, while most civilians were likely relocated to cities that could be better fortified and monitored by the military. Evidence from the Chunnel suggests that the military lost a good number of soldiers thanks to the bat guano contaminating the air with hallucinogenic gas, resulting in the once secure checkpoint now being guarded by an almost impassable few miles of toxic air. This hints that the military's numbers have lessened since those early days. It is also important to remember that the British military was not the largest group in the world, estimated to have approaching 200,000 members. That number has almost certainly become smaller in the violence of the last few years.
Overall, given the lack of further interaction with other countries, the safe bet is that the military's power in England is only strong enough to secure its borders and likely only from population centers. The walkers are probably roaming the countryside, not necessarily as an existential crisis, but still a threat that they must maintain a constant vigil over. How this will play into the current leadership of the United Kingdom is unknown as yet, but it seems that the scales are tipping between military dictatorship or a tired but united people struggling to keep their civilization alive.
