In recent years, there has been growing concern about Russian military activity around the undersea cables that form the backbone of the internet, a network of 500 submarine cables stretching hundreds of thousands of miles, transmitting terabits of data per second.

They carry 97% of global communications and are essential for transmitting government, financial and personal data. The threat of a coordinated attack could lead to massive disruptions in global communications, affecting both civilians and military operations.

Although essential, these cables are surprisingly vulnerable. Around 100 cuts are reported each year , usually caused by accidents with anchors or fishing activity.

What would happen if the entire global internet dependent on these cables were suddenly cut off?

Map of the submarine communications cables that reach Europe. TeleGeography / Wikimedia Commons. , CC BY

Minute 1: The initial confusion

For the first minute, most people don’t notice the internet is down. Apps and services that don’t require an internet connection continue to work. Only those trying to send a message or refresh a web page notice that something is wrong.

Basic operations in businesses and homes continue, although some cloud-dependent systems are beginning to show glitches. Critical services that rely on real-time data, such as traffic control centres and hospitals, may see a slight delay in their internal systems.

5 minutes: The suspicion

Within five minutes, the problem becomes more evident. Social media doesn’t update, messages don’t get sent, and those who rely on the internet for work start to worry. Messaging services and video calling platforms fail, affecting personal and professional communication.

Critical systems such as hospitals and security forces are beginning to activate their contingency plans and use radio and satellite communications to coordinate.

30 minutes: Concern grows

Half an hour later, the impact is more palpable. Telephone lines are jammed as people try to reach friends and family. Credit and debit cards stop working at stores and gas stations, causing long lines and confusion.

Banks are filled with people trying to withdraw cash, anticipating bigger problems. Traffic control systems and transport logistics may be affected, slowing down mobility and the distribution of essential products .

1 hour: Chaos in critical services

After an hour without internet, the impact on critical services becomes more evident. Hospital systems without access to digital medical records must rely on paper records, which slows care and increases the risk of medical errors . Communications between security forces are limited to radio systems and satellite phones, which cannot cover all coordination needs. At banks, the lack of access to digital networks blocks transactions and causes chaos in branches.

6 hours: Economic and social crisis

A six-hour internet blackout paralyses the economy. Financial markets are unable to operate, causing panic among investors. E-commerce and online payment platforms come to a complete halt.

Gas stations are unable to accept electronic payments, leaving many drivers without fuel. Internet-dependent security systems, such as surveillance cameras and alarms, stop working, increasing the risk of theft and vandalism .

12 hours: Desperation and vulnerability

By 12 o’clock, the situation is critical. The only sources of information are radio and, in some cases, television, but even these media are beginning to fail due to the lack of digital infrastructure. Emergency services are overwhelmed and overwhelmed by the inability to communicate efficiently.

Security forces are trying to maintain order, but the lack of coordination and growing frustration among the population are complicating the situation. Queues at banks are endless and many people are left without cash because ATMs are not working.

24 hours: Total chaos

Within 24 hours, the impact on society is devastating. Modern life, dependent on digital technology, is reduced to total chaos. Hospitals, without access to electronic systems, must resort to manual procedures. Transport and logistics services are paralysed, affecting the distribution of food and medicine. Communications between governments and international organisations are complicated, making crisis management difficult. The lack of accurate information creates confusion and panic among the population.

Privileged with alternative means

While most people are cut off, a few privileged people have alternative means of staying connected. Corporations, governments and emergency services rely on satellite communications and private networks, but even these systems have limitations and cannot replace the global connectivity of undersea cables.

A crucial role is played by radio amateurs, with more than 3,500 operating in Spain, who become a valuable resource for coordinating aid and transmitting information in emergency situations ( Union of Spanish Radio Amateurs ).

Too fragile

In conclusion, a global internet disruption would expose the fragility of our digital society. The dependence on the network for most daily activities, from the economy to security, would become alarmingly evident.

Without the Internet, our social, economic and political structure would be unprotected, which reveals the need to develop backup infrastructures and contingency strategies for possible scenarios of global disconnection.

Author Bio: Francisco Jose Garcia Ull is Professor of data analysis, privacy, ethics and AI at the European University