Barely two weeks after the United States Grand Prix at the Circuit of the Americas, the circuit created specifically for the (successful) return of F1 to the country, it emerged that after just four Grands Prix, the event is under threat.

The threat comes in the form of a serious reduction in the subsidy provided by the State of Texas, leading to COTA Chairman, Bobby Epstein, admitting: "To use a technical term, I think we're screwed."

Between 2012, the first year of the event at the circuit, and 2014, the state contributed $25m each year as part of a quarter-billion dollar subsidy agreed over the next decade with (previous) state comptroller Susan Combs.

However, for 2015, with a new governor and general staff in place, the governor's office and COTA confirmed that the state's contribution, which is based on how much economic activity the event generates for the state, would drop to around $19.5m.

Whilst Bernie Ecclestone gave organisers some welcome breathing space in allowing them - like Silverstone - to pay the (ever-increasing) hosting fees in arrears, when the official 2016 calendar appeared in December the United States event featured an asterisk and the words "subject to agreement with the promoter and the ASN".

With some feeling the event is now already doomed, a move which could prove disastrous in a country already so badly treated by the sport over the years, there is fresh hope in the shape of a letter that has been discovered from Combs, dated 10 May 2010.

According to Forbes, the letter states: "In response to the requirements of the race promotion contract for the Formula 1 United States Grand Prix in Texas, I hereby certify the following: With the understanding that the first Formula 1 United States Grand Prix race will be held in Texas in 2012, full funding of the entire sanction for 2012 will be paid to Formula One World Championship Limited (‘FOWC’) no later than July 31st, 2011.

"In subsequent years, two through ten, of the race promotion contract, i.e. 2013 through 2021, we will be sending $25 million dollars to FOWC by the end of July 31st of each year preceding the actual race event.

"We look forward with great enthusiasm to this event and a successful mutually beneficial relationship for many years to come."

In other words, the state guaranteed the annual $25m payment, and while the government has changed there is no caveat suggesting that the arrangement would be subject to change under such circumstances.

The new governor, Greg Abbott, has claimed the letter is "merely an effort to indicate broad support" but it is difficult to see how such a claim would stand up in a court of law.