In One Piece, the reputation of a Yonko often leaves others in awe. Shanks, the Red-Haired Pirate, is no exception. To date, Shanks has demonstrated his remarkable influence in various situations, including instances involving the Marines.

Below are three notable moments when the Marines were compelled to retreat due to Shanks:
1. The Battle at Marineford
In Chapter 579, the situation at Marineford escalated dramatically as Portgas D. Ace and Whitebeard sacrificed themselves.
Whitebeard unleashes the devastating powers of the Gura Gura no Mi after claiming the title, causing a massive tremor that shakes Marineford and the surrounding area. Whitebeard even threatened Sengoku and Garp, confidently asking, “Do you think you can stop me?” Furthermore, he boldly declared that the era of Whitebeard was coming to an end, leaving Garp and Sengoku at a loss.

While the Marines and Whitebeard’s crew were engaged in battle, Koby pleaded for them to cease fighting, but he was promptly silenced by Sakazuki. After that, Shanks arrived.
The Marines continued their assault in Chapter 580. Kuzan attempted to intervene and stop the conflict while Kizaru moved in (after being introduced in Chapter 579) to engage with Law’s submarine crew using the Yasakani no Magatama technique.
However, after Shanks‘s intervention, the battle came to an abrupt halt. Whitebeard’s crew and the Marines withdrew from combat, even the fierce Sakazuki chose not to continue the fight.
Clearly, this was a pivotal moment that showcased the overwhelming influence and authority of Shanks.
2. Forcing Admiral Ryokugyu to Retreat in Chapter 1055
Admiral Ryokugyu arrived in Wano, despite orders from Fleet Admiral Sakazuki prohibiting him from doing so in Chapter 1052.
When Ryokugyu fought against Momonosuke, some members of the Straw Hat crew and Yamato were nearby. They could sense the immense power emanating from Shanks‘ Haki from outside the Wano Country, prompting them to decide to withdraw.

Although Ryokugyu is a high-ranking admiral, the presence of Shanks forced him to retreat. This development left many audiences astonished.
3. Forcing Kizaru, Fujitora, and the Marines to Retreat at Elegia
This moment occurs in One Piece Film: Red and is not considered canon. However, it is still noteworthy.

In a scene from the film, Shanks uses his overwhelming Haki against the Marine forces. Ultimately, Kizaru and Fujitora decide to withdraw. If the Marines were to engage with Shanks‘ crew, the civilians in Elegia would undoubtedly suffer.
This scene emphasizes that even a high-ranking admiral like Kizaru can be intimidated by Shanks‘ influence.