If the navy chooses to send a fleet to land in Quang Ninh from the Gulf of Tonkin and it will be simple to land directly, but if it can't be quickly resolved, and finally the army will be dragged to the end and the empire will be plunged into a quagmire, I am afraid that someone in the navy will be responsible for this.

Moreover, although the navy despises the army for fear of fighting in the jungle, the navy does not dare to easily send its own marines to fight in the hinterland of Vietnam.

It is easy to land in Quang Ninh, but if you want to kill directly in the Thang Long area, the difficulty is actually similar to that of the army directly killing from the border area to Thang Long, and if you go by land, although the road is difficult to walk, there are still supplies.

Therefore, even if the navy is directly landing in battle, it is unlikely that it will directly kill Thang Long.

This is not the combat mode that the navy is good at, and the navy's best combat method is to use a powerful fleet to choose a certain coastal area to fight at will, or to attack the enemy's port city, or simply to land and fight, but it will never easily enter the interior.

The Navy's marines are not used to fight the enemy in the interior, but to carry out ship-jumping operations and landing operations, and it is the task of the army to fight deep inland.

However, it is probably unrealistic to land in Quang Ninh and attack a few coastal cities of the Anbei and Northern Dynasties to bring the Northern Dynasty to its knees and thus cede the entire Quang Ninh to the Empire.

In the pre-Ming era, the Ming army also defeated Annam, but then it was not an egg, and in the end it was forced to withdraw from Annam by the poor geographical environment and serious non-combat attrition.

As for the resistance of the local aborigines, it was actually very weak, at least it could not resist the Ming army at that time, but why the Ming army chose to retreat was not because the broken place really couldn't stay.

The garrison of 100,000 troops did nothing but spend countless money and food, and the disease alone could cause these 100,000 people to suffer heavy losses.

Although the level of medical theory in the Tang Empire is much stronger than that of the pre-Ming Dynasty, the teachers and students of the medical department of the Royal Institute of Technology have established a relatively complete modern medical system.

But the problem is, myrrh!

With the current level of medical care in the Tang Empire, there are no antibiotics or anything like that.

Nowadays, the main medical methods of the Tang Empire still rely on traditional Chinese medicine, and the pre-Ming era, there has been no essential change, at most, the concept has changed a lot, knowing to pay attention to hygiene, knowing to disinfect, knowing that the wound is infected and must be amputated in time......

The complex environment of the tropical rainforest and the diseases that are almost impossible to resist are the fundamental willingness of the Tang Empire to fight in various tropical rainforests.

Not only in the Nanyang Peninsula, in fact, in other places, the same is true of the Tang Empire, even in the two places of Banten and Luzon that they occupy, in fact, the Tang Empire still did not go too deep into some tropical rainforest areas, just built cities and farmlands along the coastline, and then relied on immigrants to spontaneously advance inland, step by step, and gradually transform the local environment.

In order to avoid fearless casualties, after consideration, the high-ranking officials of the navy felt that it was still good for the Holy Son of Heaven to say about the situation in Fusang: What to do by fighting, killing, and killing, it is good to do business!

The Son of Heaven said this because although the Tang Dynasty has not sent troops to conquer the Fusang Islands on a large scale so far, the population of Fusang has at least decreased by more than half in the past ten years, which is more efficient than the Tang Dynasty Wangshi himself, and saves time and effort.

Why?

Because the Tang Empire frequently instigated various daimyo to go to war, and sold various weapons to these daimyos, increasing the casualty ratio of these daimyos' armies.

These weapons sold at the same time all need to be purchased by the daimyo with money, and in order to obtain the weapons of the Tang Dynasty, these daimyos basically took out everything and sold it, not to mention gold and silver, other various materials, and even food and the like.

And in the past year, many daimyo have found that there is one more commodity in their ruling area that Datang needs, that is, young women!

Naturally, the marriage committee under the Datang Fusang Affairs Yamen did not directly spend money to buy women and then ship them back to China, and their policy was to recruit young Fuso women who volunteered to go to Datang.

Therefore, although those daimyo treat women as commodities, they do not mean that they are sold directly to the marriage committee, well, the marriage committee does not want it at all.

They just organized a large number of Fusang women to go to Datang, and then married them to Datang people, and their big names were to collect bride price.

The reason why there is such a situation is that after many Fusang women arrive in Datang, whether they are married or working, there will always be a small number of them who are better mixed, and then they begin to send a certain amount of money back to their relatives in China.

Thanks to the Royal Bank, which has opened branches in all the Tang colonies of Fusang, and the Datang Post Division, which has also opened branches, some of the money sent back by these Fusang women has been received by their families after a certain amount of twists and turns.

After this news gradually spread, many Fusang women just wanted to go to Datang even more, so that they could not only improve their lives, but also help their families in the future.

Then, there were clever daimyo who discovered this way to make money, and at first they just hoped to organize Fusang women to work in China through the marriage committee, and these wages were naturally taken by these daimyos.

But the marriage committee will definitely not do it, women who enter the Tang Dynasty through the marriage committee channel will all obtain the nationality of the Tang Dynasty, and you big names dare to exploit our people of the Tang Dynasty, don't die.

After a warning, no Fusang daimyo dared to do this, but they quickly thought of other ways, it is not possible to engage in labor dispatch, and Datang prohibits human trafficking, so let Datang come to Fusang to buy, no, it can't be said to be a purchase, but a marriage.

These big names organize a large number of young women, and then act as an intermediary platform to introduce unmarried Datang men, and then charge a little insignificant introduction fee, which is not a violation of Datang's law, right?

Not to mention, they are really in line with the laws of Datang when they do this!

Although Datang prohibits human trafficking, the traditional bad habit of bride price still exists, and the profession of matchmaker still exists.

A few smart daimyos contacted several Datang traders through their own channels and asked them to invite a group of single men from Datang to come over on a blind date!

As a result, the most special trade method between Tang and Fusang was born: "marriage trade"

Merchants who run to the sea, they dare to do anything, not to mention that this kind of thing does not violate the laws of Datang, so soon there are bold businessmen who return to China and recruit a large number of single dogs.

In order to avoid indifferent legal risks, they still engaged in a so-called 'Fusang tourism project', these single dogs are all traveling to Fusang, as for what they are doing in Fusang, whether to marry relatives or take concubines, and then bring these Fusang women back, they are naturally out of control of these maritime merchants, well, the marriage committee is also out of control.

After these single dogs arrived in Fuso, they were dazzled by the countless young women organized by the local daimyos, and their drooling was about to fill the East China Sea.

In the end, these single dogs, in the name of marrying, each took away several Fusang women, and although the bride price spent was a lot, it was not much compared to domestic marriage.

And then take someone straight back home!

The single dogs married women, the maritime merchants made money, the daimyo also made money, even those Fusang women also got out of the super bitter sea of Fusang and came to Datang, I dare not say how good life is in the future, but it is really not easy to starve to death.

Of course, many single dogs have a certain amount of debt for this, because most of the people who come to Fusang to marry are poor, and they don't have much money, but those maritime merchants have joined forces with some banks to get a loan for them, but it will not be too much, after all, it is easy to go to Fusang these days.

Marriage trade, after this kind of thing started, it was quickly popularized, although there was no too obvious situation in Datang in these years, but it was still a little difficult for the poor to marry.

Now everyone knows that the women over there in Fusang all want to marry the Tang Dynasty, and they are almost the same as giving them away for nothing, so many men are specially going to Fusang to marry, and those who are willing to sign up for the tour group directly, and those who are not rich in hand can also carry the cargo ship over.

After you go to Fusang, even if you are a poor bastard, a second-rate child despised by everyone in China, there will be a lot of Fusang women who are willing to post it upside down!

This situation is similar to that in China in the eighties and nineties, any American beggar can make many, especially highly educated women in the new era, lift their skirts and open their thighs.

What is done is nothing more than a green card!

The marriage trade and marriage policy on the Fuso side also led to the outflow of a large number of Fuso women, and the war in the Fuso archipelago was almost uninterrupted, and agricultural production in many areas was completely destroyed because of the war, and the total population of Fuso was decreasing at a very alarming rate.

This situation also led to the Holy Son Li Xuan saying that it is better to do business than to fight, kill and kill!

Now, the navy is thinking, although the situation on the Fuso side is a bit special, which has led to this situation, but can the Annan side also follow suit?

Not only Annam, but even the entire Nanyang Peninsula or other colonial areas, can they follow suit?

Through various ways, provoke their civil war, let them fight themselves, the empire is watching the play with melon seeds on the side, and then take the land after the play is over, simple and efficient, safe and worry-free!