Nato heads of government (front row L-R): Britain's Prime Minister Boris Johnson, NATO Secretary General Jens Stoltenberg, US President Donald Trump and Turkey's President Recep Tayyip Erdogan (middle row L-R) France's President Emmanuel Macron, German Chancellor Angela Merkel, Greek Prime Minister Kyriakos Mitsotakis, Hungary's Prime Minister Viktor Orban, Iceland's Prime Minister Katrin Jakobsdottir, (top row L-R) Netherland's Prime Minister Mark Rutte, Norway's Prime Minister Erna Solberg, Lithuania's Prime Minister Saulius Skvernelis, Portugal's Prime Minister Antonio Costaa and Montenegro's Prime Minister Dusko Markovic pose for the family photo at the NATO summit at the Grove hotel in Watford, northeast of London on December 4, 2019.

LONDON — As NATO members gather in the U.K. to celebrate 70 years since its inception, there are pressing questions about the organization's future and its relevance on the global landscape.

Leslie Vinjamuri, the head of the U.S. and the Americas Programme at think tank Chatham House, believes there will now be "several years of grappling" to reform the military alliance.

She added that one of the main issues is that the institution is not set up to deal with the current geopolitical landscape. NATO was created in the aftermath of World War II with the overall aim to protect its members against any threats posed by the Soviet Union.

But the rise of the world's second-largest economy, China, has posed new challenges to the West and trade and political tensions between Beijing and Washington have come to the fore in the last two years. The disagreements have involved the tech sector with the U.S. taking steps to ban the Chinese firm Huawei from selling its technology in the United States.

U.S. officials have expressed concern over the company's links to the Chinese government and the security threat it could pose — something which the Shenzhen-based tech firm has denied. This issue has sparked division within NATO allies, with Germany and France taking a different stance to the U.S. administration.

"NATO is at a crossroads," Agathe Demarais, global forecasting director at the research firm The Economist Intelligence Unit (EIU), highlighted to CNBC Monday.