Never has it been easier for a human being to get from one side of the world to the other; yet in some ways it has never been harder.

The trip from England to Australia took 250 days in the late 1700s. Now it takes less than 24 hours. British and Australian citizens can make the journey with ease, if we have the means to pay for a ticket. But for the vast majority of the planet getting to either destination is all but impossible. The complex rules governing human movement – who can and can’t travel, where they can travel, the issuance of documents and permissions that are required to travel etc. – are an interminable barrier.

Take the trip from Kabul to Darwin. It’s about 12 hours by air. For an Afghan acquaintance of mine, it took around three months. First, two days’ travel to Lahore, Pakistan. A two-week wait for a passport to be “arranged”. A flight to Singapore, a bribe to get through customs. A three-week wait for a smuggler to arrange a visa for Indonesia.

Another bribe, this time to police. A day in Jakarta. Then south-east to the stretches of the archipelago, perhaps Sumbawa. One and a half to two months’ wait for a boat to be organised by another smuggler. Several days to Ashmore Reef. A week on the fringes of the Indian Ocean and the Timor Sea before a two-day sail aboard an Australian customs vessel.

After Darwin came the horrors of Australia’s system of concentration camps – horrors which are publicly known, ongoing and considered legitimate by a majority of people – lasting years and from which this acquaintance, now a citizen, 15 years after landing still bears physical scars, not to mention psychological baggage. And he is considered by many to be lucky. My friend is one of tens of millions who have been displaced in recent decades; very few are accepted into new societies.

The economic relationships of imperialism are the root cause of this great displacement. They create stunted development and instability in the majority of the world in multiple ways. One is siphoning of capital. Global Financial Integrity, a US-based research organisation, estimates that the so-called developing world lost US$5.9 trillion in the decade 2001-10 via “illicit financial flows”. The figure is now running at more than $1 trillion per year.

Another is the predatory lending that leaves countries with crippling debt burdens. These act both as an economic straightjacket and a disciplining mechanism that bind governments to policies that further entrench their subordination to the West. The World Bank estimates that total external debt owed by developing countries stood at $4tn at the end of 2010; repayments run at more than $1 billion per day.

Then there is the exploitation of labour and resources by multinational companies, which are given carte-blanche to pillage so long as they pay off the right politicians. The profits from their activities largely are repatriated to the larger economies.

All of these outflows count as deductions on what could be investment in human and economic progress, leaving states unable to effectively compete in the international economic sphere. Across the African continent, for example, an estimated US$192 billion is lost every year to the rest of the world.

There is a clear link between economic underdevelopment and human displacement. Underdevelopment is a great source of social and political instability, phenomena that lend themselves to regimes with little legitimacy and therefore which are reliant on coercion and dictatorial means of governance. It also leads to a type of dependent relationship with the advanced economies, with underdeveloped countries and regions becoming the playthings of the imperial powers and sites of conflict between them.

The conflicts between the population and the regime, the violence between the competing political factions within the underdeveloped regions, or the invasions and proxy wars of the imperial powers – these are the drivers of displacement. So too do the paucity of critical infrastructure and the shoddy construction of residential dwellings result in carnage and displacement in the event of natural disasters.

So while the West constructs its fortresses to keep the mass of humanity out, the workings of imperialism create the conditions for mass displacement.