At the end of Thor: Ragnarok we see Thanos's ship over the Asgardians. All this time he has neither invaded the nine Realms nor Asgard but now he decided to come after the destruction of Asgard and the death of Odin. Is it plausible to say that because of Odin all the threats have now come to light such as Hela, Surtur, and Thanos?
it can easily be that its mere coincidence don't forget that at the end of avengers 2 he said he is going to take things into his own hands– ThomasNov 12, 2017 at 14:14
1Take a closer look at the Infinity War trailer: Thanos walks through a portal that looks suspiciously like the one Hela walked through.– DonielFDec 10, 2017 at 16:28
There's a few scenes in the film and other details that possibly answer this:
- Odin's Vault is already established in the MCU as a heavily protected vault holding several dangerous artifacts, each with the potential to bring about Ragnarok.
- Hela walks through the vault, knocking over what appears to be the infinity gauntlet inset with the Infinity Stones and stating it's fake. However, when she sees a blue cube, she notes "That's not bad," indicating the cube is real, unlike most of the other artifacts. A little bit of digging12 reveals this is the cosmic cube, which in the MCU is the Tesseract, the container for the Space Infinity Stone.
- In the hangar scene, when Loki attempts to sabotage the escape plan by raising the alarm, Thor says Loki will always be the god of mischief.
- Finally, in the bridge fight scene, when Thor sends Loki to find Surtur's crown, Loki takes interest in what we now know is the tesseract.
From all this we know:
- The Infinity Gauntlet on Asgard is fake,
- The Tesseract on Asgard is real,
- The Space Stone is in the Tesseract,
- Odin's Vault is heavily protected,
- Loki is likely to continue causing mischief and trickery
I think it's a safe bet the Vault was what prevented Thanos getting the Space Stone, and may have even prevented him knowing where it was, thus there was no reason for him to attack Asgard. It's also safe to assume Loki stole the Stone when he saw it in the vault. With Asgard and the Vault destroyed, the Stone was out in the open, and Thanos could easily find it.
All that being said, the answer may be much more simple: in the end-credits scene in Age of Ultron, after both Ronan (Guardians) and Loki fail to retrieve the Stones for him, Thanos says "fine, I'll do it myself." He may have only just started actively searching for the Stones, and the scene in Thor: Ragnarok may just be the first time he finds one.
1Have you watched The Avengers?– ibidNov 13, 2017 at 15:37
I have indeed, but not since shortly after it came out.– DavidNov 14, 2017 at 21:54
3The Tesseract was first shown in CA:tFA, where it was on earth and very much "real". In The Avengers, Thanos sent Loki to try stealing it. It's only brought to Asgard at the end of The Avengers.– ibidNov 14, 2017 at 22:04
Ah yes, you're right. However I was trying to answer using mostly or only info available in the movie (marvel wiki citations aside). The addendum at the end clarifies (I hope) that if you look at scenes in other movies, it becomes much clearer why, for example, the Tesseract is on Asgard but the Infinity Gauntlet is not, and why Thanos hasn't attacked until now.– DavidNov 14, 2017 at 22:33