Aliies very often come with a high price tag, during most times they are not assets but liabilities, US had been slowed down by its "allies" for the past several decades and China became the fastest developing countries during the same period of time without much "allies".
This is why china is short sighted while US takes a Long view of things.
US alliance ensures the dominance of the US currency. The global "rules based order" we keep hearing about is the product of the Brentton woods Agreement. Global institutions like the World Bank and IMF were created from this agreement.
British economist John Maynard Keynes and American Chief International Economist of the U.S. Treasury Department Harry Dexter White wanted to establish a powerful global central bank to be called the Clearing Union and issue a
new international reserve currency called the
bancor. While
White’s plan envisioned a more modest lending fund and a greater role for the U.S. dollar, rather than the creation of a new currency.
Bretton Woods System included 44 countries and as per the agreement U.S. dollar to be pegged to the value of gold and all other currencies in the system were then pegged to the U.S. dollar’s value.
Purpose of the IMF was to monitor exchange rates and identify nations that needed global monetary support. The World Bank, (International Bank for Reconstruction and Development) was established to manage funds available for countries devastated by World War II.
After the Brenton Woods collapsed, US pegged the Dollar to Oil and Petro-Dollar became the global currency to funnel Saudi petrodollars into U.S. Treasuries.
This gave birth to "Credit Card" that fueled US internal consumption and drove its economy.
It is this alliance that still prop up the USD and in exchange US promises to keep them Safe. In pretty much the same way the East India Company promised the smaller kingdoms of India Safety if they enter into an "alliance" with them.
Its just Indian History repeating itself on a global scale. Not by accident since this was what the British taught the US.