It is now more than four months since the dramatic exit of US and other Western forces from Afghanistan. By chartering special flights, loosening asylum rules, and releasing funds, Western countries airlifted a few thousand lucky Afghans to safety as the Taliban retook control of the country. But those left behind have been shut off from the rest of the world.

Foreign governments have frozen international banking transactions and trade with Afghanistan, mostly at the behest of the US. As a result, Afghan public-sector salaries have dried up, and the economy has tanked. Many development-aid projects, no matter how essential, have been paralysed or cancelled.

As a result, the onset of the harsh Afghan winter has brought rising prices, and food has become increasingly scarce. Schools, clinics, and hospitals across the country have stopped functioning. So, just when the Afghan people need more help, they are being denied even the basics.

International humanitarian aid workers and Afghan communities themselves are doing their best to keep food aid moving, clinics functioning, and schools open for boys and girls. But the challenges are huge. Afghans now face destitution, and even famine, on a dramatic scale.

If the status quo continues, almost the entire country faces acute poverty this coming year. By the end of this winter, almost the entire country—97 percent of the population—could be too poor to survive without aid.

The rest of the world, and developed countries in particular, should not think that they can just shut the door and forget about this mounting tragedy. Basic morality aside, the instability resulting from Afghanistan's collapse will be felt far beyond the country's borders.

To be sure, it is right to stand up for Afghan girls' education. But, as the Afghan analyst Orzala Nemat of the University of London's School of Oriental and African Studies recently put it, it is not right to withhold aid for the basic services—food, water, and health care—that keep those girls alive.

The current meltdown is a nightmare. Instead of sticking its head in the sand, the international community needs to act. There are three measures in particular that can be taken without rewarding the Taliban.

First, money must be made available. The UN will seek to raise USD 4.5 billion in 2022 to help the most vulnerable in Afghanistan. This plan is a stopgap measure for more than 21 million people who need food, shelter, medicine, and protection. The international community can surely find such a sum.

In addition, the UN Security Council recently adopted a resolution exempting humanitarian activities from the sanctions regime imposed on some Taliban members. Governments and financial institutions must make the most of this fresh opportunity.

Second, there needs to be more flexibility in how donor funding can be used. For example, the World Bank holds USD 1.5 billion in trust for Afghanistan, and recently announced an agreement to transfer USD 280 million—some to the UN Children's Fund (UNICEF) to provide health care, and some to the World Food Programme. The whole fund should now be reprogrammed to help the Afghan people.

It should also be possible to use donor funding to pay public-sector workers' salaries and to help Afghan institutions deliver basic services such as healthcare and education, and still not be seen as rewarding the Taliban. Such support for essential state functions will give Afghans hope for the future and reason to stay in their country. Hollowing out the state, on the other hand, is a recipe for suffering and instability.

Third, the international community needs to become smarter about how it engages with Afghanistan. Currently, the world is waiting for the Taliban to make progress on various international norms without clearly defining what it expects of the regime. The Taliban, meanwhile, are either not inclined to meet these expectations or opaque about their intentions.

This approach virtually ensures failure. The international community needs to be much more decisive and specific in its demands, as well as far more engaged. This could include relaxing or lifting some economic sanctions, or gradually reintroducing longer-term development assistance, in response to progress on issues of international concern—including women's and girls' rights.

The world needs to provide the people of Afghanistan the support they need, because the catastrophic consequences of failure will not be theirs to suffer alone.

Gordon Brown, a former prime minister of the United Kingdom, is United Nations Special Envoy for Global Education. Martin Griffiths is Emergency Relief Coordinator and Under-Secretary-General of the United Nations Office for the Coordination of Humanitarian Affairs.