First of all, there are some problems with this question. Ming Ge was arrested by the navy after being defeated by Luffy. Cardo wanted to save him, and he also informed his general Jack to save Ming Ge. But Ming Ge was a fool, and he dared to make moves in the face of the former marshal, so he was undoubtedly educated in the end and almost couldn't go back.

On the other hand, the world government gave up Ming Ge directly, and even wanted to kill Ming Ge, because Ming Ge knew too many secrets, and it was impossible for Ming Ge to leave him alive after his failure.

The cause and effect of brother Ming's failure

Brother Ming himself wants to use burnt fruit as bait, hold a ring match and then separate Luffy from Luo, and then break them one by one. But what I didn't expect was that there was another Saab in the competition. The appearance of Saab, instead of Luffy, caught the burnt fruit and gave Luffy the energy to deal with Brother Ming. And Ming Ge misjudged Luffy's strength, so he finally lost to Luffy's fourth gear.

In Dresden, Ming Ge made several mistakes, which made the world government unable to protect him. Even if Ming Ge's identity is Celestial Dragons, the world government has no way to save him, only to keep him silent. Ming Ge's first mistake was that he didn't hide it after he occupied Dresden.

Because this time, the general sent by the navy was a rattan tiger, and Ming Ge didn't think about it at all. He is unscrupulous because of his status as Celestial Dragons and Qiwuhai, but rattan tiger's character can't be rubbed into the sand in his eyes, so it's unbearable to see Ming Ge so arrogant and evil.

Another mistake is that Brother Ming is too ambitious. Brother Ming wanted to arrest all the pirates at that time. Although Tangtang's ability is really strong, it is not invincible, and Ming Ge actually angered all pirates and became the target of public criticism, so Ming Ge finally failed. He didn't just lose to Luffy's men. To be precise, it was lost to the joint efforts of everyone in Dresden. He has stood on the opposite side of the public, can't win, and basically fails.

Why the world government doesn't protect Ming Ge.

Of course, the first reason is that Ming Ge failed. Ming Ge is one of the seven seas, and the world government has no mercy on the failed seven seas. From Crokdal and Moria before, we can see that the attitude of the world government towards the failure of the Seven Seas is very strict. As long as it fails, it has no value in the eyes of world governments.

So it must be erased. Although this shows that Brother Qi Hai is not an ordinary person, his real identity is Celestial Dragons, but this ending is inevitable. No matter who it is, as long as it is useless to the world government, the world government will naturally not go easy on him.

There is a second reason. Brother Ming has gone too far. Brother Ming is one of the seven seas, but it's okay to make a little mistake. However, Ming Ge occupied Dresden, an ally of the world government. If this fact was not discovered, there would be no problem, but it was discovered by Admiral Fujitsu.

Moreover, after being discovered by Fujitsu, Ming Ge did not think about how to make up for this mistake, but completely ignored it. Even after the pirates' cadres in Ming Ge were knocked down, Ming Ge tried to shoot everyone in the mouth with a birdcage.

Now, no matter who, it is impossible to keep Ming Ge. Ming Ge has no scruples about a country's royal family, and shows no mercy to the allied navy. He has lost his mind. In this case, it is impossible for the world government to keep Ming Ge.

The last reason is that Ming Ge knows too many things that he shouldn't know. Ming Ge is one of the 20 families that established the world government in Celestial Dragons.

Ming Ge's strength and status are much higher than that of ordinary Celestial Dragons, but this kind of thing is not a good thing. When Ming Ge is in power, the more he knows, the better. The more he knew, the greater his value, but he was abandoned after Ming Ge failed.

It is not good to know too much at this time. Sometimes ignorant people are the happiest. The more people know, the faster they die. Ming Ge is like this. Because he knows too much, he has lost his value. Therefore, the world government led by Celestial Dragons naturally wants to kill Ming Ge. Otherwise, if Ming Ge finds out the secrets of Yu Tianlong people, it will be too late. So even if Ming Ge is locked in the promotion city, the world government will send someone to assassinate Ming Ge.

Cardo didn't save Brother Ming's original regiment.

Kaiduo has sent his man Jack to save Brother Ming, because Jack was the only one of the three disasters at that time, so Jack should be the only choice to save Brother Ming. Even if Kay wanted to send two more people to save Ming Ge from these three disasters, it was already too late. It is estimated that they have been sent to the promotion city before Ming Ge. If Jack can't save them, it's no use sending two others.

Of course, Cardo has a second choice, and that is to save Brother Ming himself, because Cardo's demon fruit has the ability to fly after becoming a dragon.

Kado could have turned into a dragon to save Ming Ge, but Ming Ge was not so valuable. Ming Ge's role for Kaiduo is to make artificial devil fruit to enhance the strength of Kaiduo Pirates Group at the grassroots level, but Kaiduo Pirates Group relies on the strong, and the grassroots level is also very important, but it has not yet played a decisive role.

In addition, if Kado saves Ming Ge himself, it will represent a full-scale war with the navy and the world government, which is unacceptable to Kado. With the current strength of Kaiduo, it is still difficult to go to war with the world government, so Kaiduo can't save Ming Ge himself, which also leads to Kaiduo having to give up Ming Ge after Jack's failure.