According to the British "Navy Outlook" website, British Defense Secretary Ben Wallace recently ordered a six-month survey to determine whether the equipment development of the Royal Navy should focus on surface or underwater power construction in the future. He revealed that he was inclined to invest more in underwater fleet construction. It is reported that since 1970, the number ratio of British naval surface ships to attack nuclear submarines has remained between 4:1 and 3:1. Although the number does not represent the strength, it reflects the importance it attaches to underwater power. However, in the past 10 years, this trend has changed - the Royal Navy is investing more and more funds in the construction of surface ships, especially frigates. The construction of underwater forces is affected and limited by insufficient funds and weakened industrial construction capacity. Ben Wallace pointed out that we must be alert to this situation. He said that the British navy needs to equip more submarines, because submarines are power multipliers for maritime operations. They can not only help the navy to seize the sea power, but also create favorable operational conditions for other forces. The "Navy Outlook" website agrees with this view, and believes that the attack type nuclear submarine is very suitable for carrying out high-intensity offensive combat tasks. According to the article, if the British Navy is equipped with a large number of attack type nuclear submarines or conventional submarines, it will be able to form an effective deterrent to potential opponents, "no matter how many frigates or destroyers are equipped, this cannot be achieved". From a theoretical perspective, the British Navy has three options, namely, building more offensive nuclear submarines, conventional submarines, or building a large-scale unmanned submersible fleet. From a practical perspective, the first two schemes are very difficult to achieve. British media believe that British shipyards will not be able to build attack type nuclear submarines until at least 2039. Moreover, even if the construction plan is completed, the British Navy also lacks sufficient manpower to operate and maintain these submarines. It is more difficult to build a conventional submarine. Since the 1980s, the UK has begun to pursue a "full nuclear powered submarine fleet". Now, if you want to equip advanced conventional submarines, you need to buy them from Germany or Japan. "This will face great political resistance". In this view, the most realistic choice for the British Navy is to build a large-scale unmanned submersible fleet. At present, the Royal Navy has launched a low-cost "manta ray" unmanned submersible project, and hopes to cooperate with the U.S. Navy and Boeing to develop a super large unmanned submersible. Unlike the British Ministry of Defense, which tends to focus on the development of underwater forces, the British Navy generally believes that underwater forces such as submarines are not omnipotent. A mature navy must develop in an all-round and balanced way and have a variety of platforms capable of performing underwater, surface and air missions. Then, the only way to break the situation is to increase military expenditure. British Prime Minister Elizabeth Trass had previously announced that she planned to increase British defense expenditure to 3% of GDP by 2030, which means that British military expenditure will increase to 100 billion pounds (1 pound is about 7.8 yuan). However, most analysts believe that this is an impossible task