Warning: contains major spoilers for Avengers Mech Strike #4!
Iron Man could have been responsible for inspiring Thanos' Infinity War plan. Avengers Mech Strike #4 sees the Avengers partner with Thanos to defeat Kang. However, Earth's mightiest heroes nearly ruined their own future when meeting with the Mad Titan.
Thanos has always been one of the Avengers' biggest foes. Fans were able to see his insane plans at work in Avengers: Infinity War (2018). By gathering the infinity stones, the Mad Titan had control over time, space, and reality amongst other things. This led to half of the population being snapped away. The infinity stones have a lot of power which can be used for good or evil. With Thanos, the power ends up being used in a destructive manner the Avengers see as evil - though Thanos saw it as a solution to the universe's problems.
Avengers Mech Strike #4 was created by Jed Mackay, Carlos Magno, Guru-eFX, and VC's Cory Petit. In this issue, Thanos officially joins the Avengers to fight against Kang. The Mad Titan isn't pleased to have been plucked out of time and inconvenienced by Kang the Conqueror. Nonetheless, he likes some of what Kang is doing and by pointing out Kang's achievements, Iron Man has placed a very particular idea into Thanos' head.
Kang the Conqueror has "total control of time and reality" - a phrase which Thanos repeats after Iron Man points it out. This version of the Mad Titan hasn't met the Avengers yet and therefore hasn't collected the infinity stones. Yet the Avengers know exactly what Thanos has done since they've lived through facing him already. By pointing out Kang's current powers in front of the Mad Titan, Iron Man has planted the seed of Thanos' plan. Even without mentioning the infinity stones, it shouldn't take much for the supervillain to begin evaluating ways to replicate what Kang is doing in his own way. The question is: does this stick and cause Iron Man to be the Earth's undoing?
Thankfully, no, he's not. This timeline is safe from Thanos' Infinity War plan from happening - or whichever timeline this particular iteration of Thanos would have attacked. Ironically, it is safe because of Kang. When the Avengers go to face Kang, the Mad Titan is with them. He is very eager to fight his foe and charges in immediately - only to find himself ruined by the very thing he had begun wanting. Kang's control of time allowed him to age Thanos rapidly, right into death itself. As a result, the idea that Iron Man accidentally planted into his head was gone just as quick as it had been gifted.
It seems inevitable that Thanos would want the kind of power that Kang has here, but giving the idea right to him is highly self-destructive, even if unintentional. Even though Iron Man was able to get out of this particular situation without further complication from Thanos, it is worth noting that even just discussing another villain's abilities or plans in front of a villain can be a means of causing more trouble - even if the information is very important to know when planning an attack. Infinity War is always going to be one of Thanos' major plans, but it's better to let him take the time to have the idea himself than to accidentally give it to him and bring it to fruition faster.