In the wake of President Biden's faltering performance in last week's debate, foreign leaders heading to Washington for the upcoming U.S.-hosted NATO summit are increasingly concerned about the possibility of a second Trump presidency. The summit, initially seen as an opportunity to showcase Biden's global leadership and secure a foreign policy victory, now takes on new meaning as allies fret about the future of NATO under a potential Trump administration.

The summit's agenda remains focused on key issues such as support for Ukraine, its path toward NATO membership, alliance unity, burden-sharing, and modernization. Biden's national security team is preparing his remarks for the main summit meetings and organizing bilateral sessions with individual government heads on the sidelines.

However, Biden's debate stumbles have amplified existing apprehension among many alliance members. They fear that his reelection campaign is in trouble and that a return to the troubled years of Donald Trump's disdain for NATO could be looming. This concern is shared by both U.S. and foreign officials, who spoke anonymously to discuss sensitive diplomatic and security matters.

The upcoming three-day summit, with nearly 40 leaders in attendance, puts Biden under intense scrutiny as the most important NATO leader. Any misstep could have political repercussions. Despite concerns about Biden's health, administration officials emphasize that there have been no plans to limit the president's exposure at the summit. A solo news conference, initially tentative, has now been firmly scheduled.

Leaders attending the summit see it as an opportunity to assess Biden personally and make strategic plans accordingly. They will closely observe the president's behavior during various interactions, including plenary meetings, a reception, a dinner for leaders and their spouses, and one-on-one sessions. The political overtones of the summit, given its timing and location against the backdrop of the ongoing debate and the upcoming Republican National Convention, cannot be ignored.

Analysts warn that questions about Biden's mental acuity and physical stamina have already become a major distraction that could undermine the summit's goals. However, a strong performance by Biden could alleviate concerns and bolster confidence in both his future and the Democratic Party's prospects, shaping the perception of his leadership on the global stage.

The White House, while dismissing the debate as a "bad night" for Biden, has focused on highlighting NATO's successes during his term. From unity and support for Ukraine to the admission of new member countries like Sweden and Finland, the administration aims to showcase Biden's effective leadership in strengthening the alliance.

Amid ongoing skepticism, testimonials from foreign leaders who have personally interacted with Biden have been put forward to counter doubts about his capabilities. German Chancellor Olaf Scholz and Israeli Prime Minister Benjamin Netanyahu have praised Biden's experience, clarity, and focus.

As the NATO summit approaches, Biden's strengths come into play. The event provides him with opportunities to engage with friendly leaders and be at the center of attention as they present requests to the United States. Moreover, his position as a buffer against the potential drama and disruption caused by a second Trump presidency reinforces his importance in the eyes of many NATO countries.

However, even before the debate, several NATO countries had begun hedging their bets, seeking connections with potential future members of Trump's foreign policy team. This effort reflects their desire to understand how a Trump administration would position the United States in the world and gain favor.

As the summit approaches, embassy staff and officials will compare notes and assess the credibility of Trump's threats and promises. The corridors of the event will likely be filled with discussions about the potential implications of a Trump return to power.

The NATO summit serves as a critical juncture for Biden to prove his leadership and assuage concerns among allies. While the focus remains on the shared goals of the alliance, the political backdrop and fears of a Trump resurgence inject a sense of urgency into these deliberations.