The upcoming NATO summit in Washington this week is an important moment for President Biden to show that he is still mentally and physically capable of leading the alliance. There are widespread concerns about Biden's age and mental fitness after his debate performance against Trump raised questions. NATO's main focus is currently supporting Ukraine against Russia's invasion, but this could be in jeopardy if Trump wins the 2024 election. Trump has previously threatened to withdraw US support from NATO if members don't increase defense spending to 2% of GDP.