Warning: huge spoilers ahead for Episode 4 of Game of Thrones Season 7, "The Spoils of War." If you haven't caught the episode yet, feel free to check out some of our non-spoilery Game of Thrones coverage!
Season 7 of Game of Thrones has been delivering big scenes that fans have been waiting years to see on the small screen, ranging from Dany and Jon actually meeting to Nymeria entering the scene again. The main players are finally coming together, and the game has become more of a bloodbath than usual as the end approaches. Ever since Daenerys emerged from a fire with three baby dragons and a vow to take the Seven Kingdoms, we've been waiting to see her unleash her children and start roasting her enemies. Well, "The Spoils of War" finally gave us Dany on the back of a rampaging dragon in Westeros, and the Seven Kingdoms might be totally screwed.
Frustrated by the destruction of a huge chunk of her fleet courtesy of Euron Greyjoy and the failure of Tyrion's grand plan to take Casterly Rock by surprise, Dany decided that she was done with plotting clever plans for the time being. The time had come to deal a big blow to her enemies, and that meant bringing out the Dothraki and Drogon. A shrieking Dothraki horde charged on Westerosi soil for the first time, and we learned just why Dothraki warriors are known as "screamers." The Lannister forces nevertheless had a strong enough position and enough armor to at least make a good fight of it. Then, Dany flew in on Drogon, scaring the hell out of the Lannister army, including Jaime and Bronn.
The army understandably panicked, and the Dothraki were able to break through their lines and start the kind of slaughter that the knights and foot soldiers of Westeros had never experienced before. Meanwhile, Dany and Drogon roasted any soldiers who got in their way and unleashed dragon fire on the Lannister supply line, burning what they'd managed to pilfer from Highgarden after they took the castle and forced Lady Olenna's hand. While the episode ended before we could see the aftermath, the battle was clearly a major victory for Dany, and a totally badass sequence to watch.
That said, the battle may have revealed that Dany's methods of warfare will doom more than just the Lannister army. Thanks to the counsel of Tyrion and Jon Snow in "The Spoils of War," she was talked out of taking King's Landing by force and burning Cersei out of the Red Keep, but flying in on Drogon with a horde of Dothraki screamers still may be enough to unite a lot of people in Westeros against her. Although he did fail to take Drogon down permanently, Bronn with the scorpion proved that the dragons can be killed. The whole war might have ended in this one battle if he'd struck Drogon through the eye and sent him falling from the sky with Dany on his back.
Ser Jorah also proved back in Season 1 that Westerosi armor can stop the curved blade of a Dothraki arakh; if the knights are able to mentally prepare for a fight against Dothraki, future battles could turn out very differently. If Dany's slaughter does manage to unite people of Westeros against her, she may find herself forced to roast a lot more than just the Lannister soldiers if she wants to stay in the game, and winning the Iron Throne by bloody conquest on dragon back might result in her not holding the Iron Throne for very long. She can't roast everybody.
Then again, maybe Dany's decision to unleash Drogon and the Dothraki will be enough to convince some of the remaining lords and ladies of Westeros to bend the knee to her rather than band together against her. Conquest by dragon worked for Aegon the Conquerer, and the result was a powerful Targaryen dynasty that lasted for 300 years. Perhaps this first battle will be enough to remind folks what happened when Aegon arrived and motivate them to bend the knee right away, putting an end the civil war and opening the show up for the Great War to begin in earnest.
Even if that does happen, however, the fact remains that Dany and Drogon just burned a whole bunch of supply wagons, and we've heard time and time again in Season 7 that supplies are already running short throughout the Seven Kingdoms. The people of King's Landing may begin to starve a lot sooner than they would have if not for Dany and Drogon, to say nothing of the people of the Reach whose crops were taken by the Lannister army. The smallfolk were already in for a hungry winter; now, many of them may starve, and all the dragon fire in the world won't be able to feed them. Even if Dany's goal isn't to make the common people suffer, they'll likely suffer all the same, perhaps even more than they would have if she'd just stayed on Dragonstone.
Throw in the reality that Cersei is not going to surrender, and the death toll may be astronomical before the Great War even begins and the White Walkers (presumably) make it past the Wall. Cersei isn't quite as off her rocker as the Mad King Aerys was by the end of his reign, and she may not be willing to burn all of King's Landing to a crisp if that meant stopping somebody from usurping her throne, but she'll undoubtedly go pretty far, and she has the support of the Iron Bank of Braavos.
Basically, the Seven Kingdoms might be totally screwed. The War of the Five Kings might become a fond memory compared to Dany's conquest with her dragons, Cersei's defiance, and the upcoming Great War. Whoever wins the Iron Throne may end up as the ruler of scorched lands, burned crops, a starved population, and a continent littered with the bodies of allies, enemies, and ice zombies. As spectacular as the entire battle was as Dany unleashed Drogon and her Dothraki, it may have been the first definitive sign that continued civil war is unsustainable now that winter has come. Unless something big changes, victory might come at a terrible price for whoever ends up on top. Where's Azor Ahai when we need him/her?