The carrier strike groups sent to the Indo-Pacific is only half of US Naval firepower. The US Navy's submarine force is part of the naval firepower sent to keep the PLA Navy in check.
As the surface fleet was having breakouts, the US Navy's Pacific Fleet submarine force was in deep into the frontlines in 'contingency response operations' deployed in the Western Pacific to support the US 'free and open Indo-Pacific' directive to counter China, reported National Interest.
Contra-narrative to Communist China
Contrary to what the Chinese communists say, the US Navy was never hobbled totally. To plug the gap, the US Navy sent several ships like the USS Independence and other LCS combat ships, Arleigh burke-class destroyers into the freedom of navigations operations (FONOPs) with the support of America sea wolves.
According to the Honolulu Star-Advertiser, seven subs or an undisclosed number with Guam-based attack submarines, while submarines from Hawaii were sent to the Indo-Pacific. The objective was to demonstrate that US naval power is flexible and adaptable. The US Navy only declares the presence of their silent attack subs to relay to China to watch out the Navy is watching. During the pandemic, the US displayed its capacity and assets showing its lethality which is feared by the PLA Navy.
One of the sidelined carriers the USS Theodore Roosevelt was in Guam during March to quell an outbreak amongst its 4800 crew. Later the Associated Press said the fighting ship and its crew can get back to service soon. Some reports said that it will leave port with 1800 crew in quarantine, at that time.
US Subs counters PLA Navy
So, the carriers were sidelined for a while the US Navy do not have carriers. It is the US Navy's Pacific Fleet submarine force that possesses access beneath the sea, the undersea passage gives the speed needed to respond to any problem in the Indo-Pacific. There's an announcement by the US Navy that subs are training for engaging the enemies of the US and undersea warfare tactics to support all vessels in many missions.
In a statement, the U.S. Pacific Fleet Rear Adm. Blake Converse, Submarine Force boss said that the US Submarine Force are ready anytime to rally forth, and go anytime or anywhere. Citing that the American sea wolves are dangerous, maneuverable, can fight any time when called.
In the Western Pacific, submarines will keep the balance in check that includes the East with South China Seas to watch over the buildup of the Chinese ambitions in particular. US submarines that are nuclear powered, and with a ballistic missile that can be armed with nuke warhead, is key to the US arsenal, cited ASPI The Strategist.
During the exercises in the Philippine Sea, three subs from the 7th fleet trained with surface ships. The objective is to orient surface crews in fighting possibly Chinese subs above water and underwater.
Rear Adm. Jimmy Pitts, Commander, Submarine Group Seven (CSG7) said that success for submarine service is in diverse missions and integration with all Navy units to achieve success in all aspects of the operation.
Admiral Converse said that all operations are to defend interests and freedoms concerning international law.
US Naval command states that the US Navy's Pacific Fleet submarine force is ready for all kinds of military operations for all warfare capabilities and deterrence anywhere on the globe.