USA - American supremacy is on the line as a historian has issued a dire warning about the impact debt could have on the country. Professor Niall Ferguson has warned the US's global status would suffer devastating consequences if politicians continue to ignore the country's worsening debt crisis. Professor Ferguson noted both President Joe Biden and his likely contender in November's presidential election, Donald Trump, have heavily contributed to increasing America's debt during their presidencies. The history cited historical examples to outline the potential consequences the US faces as he noted records showed that interest payments on national debt overtook defence spending in June. And earlier this week, the Congressional Budget Office (CBO) estimated that another $1.9 trillion will be added to America's national debt by December.