Smaug is Not The Strongest Dragon Undeniably, Smaug is the Greatest Dragon left in Middle Earth during the Third Age. Yet, he is not the strongest in its history. That title falls to Ancalagon the Black, the largest dragon ever to have existed in Middle-earth.
So, one glimpse into Smaug's eyes and the Balrog falls under the spell. Even if it's just for a second—a moment of hesitation or distraction, it'd be enough. Smaug would snatch up Durin's Bane and gobble him up with his sword-sharp teeth (and we know swords can kill Balrogs).
Basically, no. Drogon is a very young dragon and still barely large enough to get Dany into the sky… Smaug is gigantic, not to mention that Smaug talks and would probably have an intellectual advantage.
Although both the Balrog and Smaug are creatures of fire, and Gandalf is able to match them thanks to the power of his fire ring, defeating the Balrog takes far more spiritual prowess, which is why Gandalf is able to essentially 'level up' and comes back as Gandalf the White, whereas defeating such an immense physical ...
Smaug's dragon-fine would not have been hot enough to destroy the One Ring. The malevolence that Sauron put inside of the Ring could only be destroyed in the Cracks of Doom, so Frodo was compelled to make the journey to Mordor.
Bilbo is terrified, but goes to confront Smaug because he wants to give the dwarves a chance to obtain the lives they deserve.
Sauron allied with Smaug and intended to use the dragon's powers against the people of Middle-earth. But before that could happen, Smaug was slain by Bard the Bowman.
Gandalf absolutely could have killed Smaug in a one-on-one fight. The grey wizard fought and defeated the Balrog of Moria, and a dragon was a lesser evil than that.
Barring Ancalagon, the only other dragon that can be bigger than Smaug is Glaurung thru implications in the text + an illustration that puts him at a whopping 350 meters length, whilst Smaug at the highest is 150 meters long.
The most powerful dragon to ever exist since the dawn of time in Middle-earth, and the chief of the Winged Dragons of the War of Wrath, is Ancalagon the Black.
Smaug surely has the physical capacity to kill Sauron (or at least incapacitate him temporarily - he couldn't kill him for the same reason the flood of the Bruinen couldn't kill the Nazgûl), but he would never oppose Sauron directly.
Smaug is still a huge and devastating beast, especially compared to little Bilbo Baggins, but Balerion's height comes out victorious. However, Smaug was far from the largest Dragon in Middle-earth, as some are said to be as big as a mountain.
1 Night Fury
While Toothless showed how kind and compassionate a Night Fury can be, he also shows that their destructive capabilities, proving that they're the strongest dragons in How to Train Your Dragon.
The fall of Gondolin and the fall of Troy
The Elf Ecthelion leads the charge against the Orcs, and fights Gothmog, the greatest Balrog; they wound each other and both fall into the king's fountain in Gondolin; both drown.
Gandalf was scared of this beast because he knew how powerful it was since it was a Maia like himself, but it was purely evil.
Smaug was the last named dragon of Middle-earth. He was slain by Bard, a descendant of Girion, Lord of Dale.
All four were killed in the ensuing Battle Above the Gods Eye, when the dragons locked together, Caraxes's jaws closed around Vhagar's neck, Daemon leapt from his dragon to Vhagar to put Dark Sister through Aemond's eye, and the dragons crashed into the lake.
He Was The Last Great Dragon
Tolkien confirmed in a letter that Smaug was the last of his kind; and the last of the Great Fire-drakes of Middle Earth. This implies that dragons of lesser stature, such as smaller Cold-drakes or Fire-drakes, may have lived on.
However, Balerion outlasted all of his counterparts, and took part in some of the most pivotal events that shaped the Seven Kingdoms for generations. He was ridden by Aegon the Conqueror when he set out to take over Westeros.
He decides to go back down to Smaug and see if he can find his weak spot. Bilbo is invisible because he is wearing his ring, but Smaug can smell him. They talk about the treasure-trove and the dwarves' intent to reclaim it.
Smaug is a dragon whose evil, like Gollum's, is indicated by his isolation. He lives alone in the Lonely Mountain, his only purpose to guard the treasure he stole from the dwarves during the reign of Thorin's grandfather.
Yet, with Smaug being a dragon, he may have shared the same traits as real-world reptiles -- most notably, their ability to go long periods without eating. Many reptiles have a form of hibernation called brumation, where they'll slow down to conserve energy over winter and not require any food.
He was only worried about finding the Ring, and he already had plenty of servants to do that for him. So, in short, the power that Sauron would have gained by recruiting the Balrog wasn't worth his time.
He lost even more power at his defeat at the end of the second age to the last alliance. So, War of The ring, Sauron would of only had the power to seduce Smaug with promises of greater fortune and power. He wouldn't of been able to physically or mentally command him.
Smaug's ability to speak, the use of riddles, the element of betrayal, his enemy's communication via birds, and his weak spot could all have been inspired by the talking dragon Fafnir of the Völsunga saga. Shippey identified several points of similarity between Smaug and Fafnir.