Since Yuan Shikai became the provisional president of the Republic of China, his political ambitions have been swelling, suppressing and killing revolutionaries, tampering with the constitution, undermining the responsible cabinet system, treating the cabinet as his "back garden", strengthening the power of the president, and even dreaming of restoring the imperial system. On this chessboard of restoration and emperor, one of the places that made Yuan Shikai's head big was that the remote provinces of Yun and Gui were not completely controlled, and in order to prevent the formation of local separatist regimes to confront him, Yuan Shikai transferred Cai Wei to Beijing to co-opt and monitor.
At that time, Cai Wei was not afraid of Yuan Shikai's threat, after all, as the governor of Yunnan, he held military power, won the support of the people in Yunnan, had certain political achievements and prestige, and had the ability and capital to "be exempted from foreign military orders". However, he still entered Beijing with the naïve dream of assisting Yuan Shikai in building a strong Republic of China. On October 9, 1913, Cai Wei left Kunming, first from Vietnam to Hong Kong, and then took a ship through Shanghai, Nanjing, and Shandong. Whenever he arrived, Yuan Shikai would send commissioners to greet him, greet the horses and horses, and set up a banquet with the wind. When he arrived in Beijing, Yuan Shikai gave Cai Wei some nominal idle posts, such as member of the Political Council, participation in politics in the Senate, general of the General's Office, clerk of the Army and Navy Command Office, and supervisor of the National Economic and Boundary Bureau. Cai Wei, who had the heart to serve the country, knew that Yuan's letting him go to the Economic Boundary Bureau was perfunctory, but he believed that the Zhengjing Circle and Qingtianfu were also important in governing the country, and he wanted to make some achievements. However, in just half a year, he presided over the compilation and printing of two major works, "Minutes of China's Historical Economic Circles" and "Minutes of Economic Circles of Various Countries", which shows that he is serious, down-to-earth, meticulous and rigorous in his work.
Within a year or two of Cai's arrival in Beijing, he witnessed Yuan Shikai's manipulation of the revision of the Presidential Election Law and the cancellation of the Provisional Treaty, and the achievements of the Xinhai Revolution were completely destroyed except for the signboard of the Republic of China. In August 1915, at the behest of Yuan Shikai, a "Preparatory Security Council" and "National Petition Federation" appeared in Beijing under the banner of "preparing for the security of a country", creating public opinion and singing praises for the restoration of the imperial system.
While the Preparations were brewing, Cai Wei and Liang Qichao secretly discussed in Tianjin, which made him determined to oppose Yuan Shikai's restoration of the imperial system. He also preliminarily drew up a strategic idea of launching an armed uprising in Yunnan. The main content is: "Yunnan ordered Yuan to declare independence after the emperor, Guizhou responded after one month, Guangxi responded two months later, and then went down to Sichuan with the power of Yungui, Guangdong with the power of Guangxi, and after three or four months, it can meet Hubei and determine the Central Plains." From this time on, Cai Wei contacted relevant personnel in Beijing and China, exchanged secret telegrams with military and political personnel in the southwest, secretly sent special envoys to Guangxi, Hunan, and Guangdong for consultations, and also got in touch with Huang Xing, who was far away in the United States. While Cai Wei was secretly plotting, he also had to deal with Yuan Shikai's suspicions. Only half a month after the "Preparatory Security Council" was put up on its signboard, Liang Qichao published his long article in more than 10,000 words in major daily newspapers in Beijing and Tianjin, "The so-called national body problem of the country", which shocked China and abroad and recited it for a while. As Liang Qichao's proud protégé, Cai Wei declared in Beijing: "Our husband is a nerd and does not know the current affairs." Someone asked rhetorically: "Then why don't you persuade your teacher?" Cai Wei replied: "Where can the nerd persuade, but the nerd will not do anything, why bother with him?" He even initiated the establishment of a "discussion committee to discuss the state of affairs" and publicly expressed his support for Yuan Shikai to be declared emperor.
In order to reduce Yuan Shikai's vigilance, Cai Wei began to set foot in the eight hutongs of the capital, creating an image of flowers and wine. Hence the nickname "Merry General". The story of Cai Wei and Xiao Fengxian, which is passed down by the world, happened at this time. Cai met Xiao Fengxian in the Bada Hutong, which was also an inevitable part of his defense war before it began.
The frequent exchanges between Cai Wei and Xiao Fengxian led to Cai Wei's family turmoil, causing the husband and wife to turn against each other. This incident not only alarmed the neighbors, but also alarmed Yuan Shikai, which directly made Yuan Shikai's defensiveness against him dissipate by more than half. After mediation, Cai Wei paid tens of thousands of alimony and divorced his wife. Cai's mother was dissatisfied with her son's obsession with wine and could not bear her grandchildren, so she returned to Hunan with Mrs. Cai and left the capital. The departure of the family made the thousand pounds of big stones hanging in Cai Wei's heart fall. Since then, Cai has used the Ba Da Hutong brothel as a place of contact with all parties.
After Cai's family left Beijing, Yuan Shikai received a report from a spy that Cai Wei had secretly communicated with the outside world. He then sent plainclothes military police to break into Cai's home, rummage through boxes and cabinets, search for telegram letters, and found nothing. Cai Wei had taken precautions in advance and brought the relevant letters and telegrams to Liang Qichao's home in Tianjin for storage.
In order to try to escape and not attract Yuan Shikai's attention to the Yunnan side as a precaution, Cai Wei wrote to Yuan Shikai several times to ask for leave for treatment, while secretly planning to escape. Cai Su has an old disease and is in poor health, so treating the disease is not like an excuse. According to the information in the Government Gazette, from October to late November 1915, Cai Wei asked Yuan Shikai for sick leave four times, and the medical treatment places ranged from Beijing to Tianjin to Japan, and Yuan Shikai approved them all. When the ship arrived in Japan, Cai Wei and the person sent by Huang Xing exchanged clothes, and the other party disguised as Cai Wei and disembarked for medical treatment. The real Cai Wei has returned to Shanghai by boat, then traveled to Hanoi, Vietnam, via Hong Kong, and then went straight to Kunming, Yunnan by land.
On December 13, 1915, Yuan Shikai announced the restoration of the imperial system, officially called Emperor, and changed the name Hong Xiannian.
On the evening of the 22nd, he and 37 others fought in blood, and his oath read: "It is the duty of my generation to support the republic." Xingshi rebelled and vowed to destroy the thieves. Success or failure is blunt, and solidarity is the same. Thousands of hardships, sacrifice of life. Wherever I am with others, persevere in concentration. With this alliance, the gods will perish. After that, they sent Yuan Shikai the famous first telegram of the War to Protect the Motherland, "Yang Dian": "The driving force behind the change of the national system actually came from the Jingshi Division, and the people who caused the first disaster were all the hearts and spleens of the great president." The security committee advocated by Gai Yangdu and other six people was instigated in the front, while the telegrams sent by Duan Zhigui and others from various provinces contributed to Yu Ji, and the great president knew but did not commit crimes, and the people were confused. Then, the telegram demanded that Yang Du and six others and Zhu Qijun and seven others be sentenced to thank the world. At the end of the message, Yuan Shikai was asked to reply within 24 hours. Yuan Shikai did not respond. Therefore, on December 25, Tang Jiyao and Cai Wei telegraphed the whole country, declared Yunnan's independence, raised troops to beg Yuan, and opened the prelude to the War to Protect the Country. When taking the oath, Cai Wei said: "My nephew has no choice but to do this righteous act today, if I dare to Yun, I will be able to save my life, and I will only fight for the people of the mainland to recover a person." ”
Cai Wei led four echelon regiments (brigades) of the First Army with about 8,000 men into Sichuan, intending to surprise the enemy forces on the Sichuan side, winning a surprising victory, capturing the important places of Xuzhou (present-day Yibin) and Luzhou, and then attacking Chengdu in the north and Chongqing in the east, and then moving east to join Wuhan. The National Defense Army, with its weaker forces than the enemy, fought for several months with the so-called elite Beiyang Army under the condition of a shortage of ammunition and ammunition and intermittent support in the rear, and although it did not capture Luzhou, it contained the main force of the enemy army, prevented the advance of the enemy army, effectively cooperated with the actions of the army in other directions, and promoted the development and growth of the national anti-imperialist movement. On March 22, Yuan Shikai was forced to announce the abolition of the imperial system.
On June 6, 1916, Yuan Shikai died of illness, ending the War to Protect the Motherland. Cai Wei was appointed as the overseer of Sichuan. At that time, Cai Wei had a high prestige in the country and was regarded as a "military god".