Keren Weitzberg is a fellow at the Institute of Advanced Studies and the department of history at University College London. She is the author of the book "We Do Not Have Borders: Greater Somalia and the Predicaments of Belonging in Kenya."

President Trump has focused on constructing a wall. But maybe we would be better served by deconstructing our notion of borders. (AP/Gregory Bull)

Borders loom large in President Trump’s politics. On the campaign trail, every perceived slight led to a pledge to make his promised wall on America’s southern border 10 feet taller. As president, he has focused intermittently on the dividing line between the United States and Mexico, suggesting that the best way to keep out the “animals” is to shore up “America’s weak borders.” He has even threatened to shut the government down to secure funding for his wall.

Trump is not wrong in his belief in the political power of national lines. The key to the successful management of immigration involves borders: how we imagine them, the power we give them. In order to see that power at work, though, it helps to move outside the North American context, to a place where boundaries are conceived very differently.

In Africa, where heavily securitized borders are not the norm, it is easier to see the nation-state for what it is: a political invention. African efforts to rethink colonial boundaries are suggestive of possibilities for countries the world over. We may think of our inherited borders as immutable, but they are in fact the result of messy, contested historical processes.

All too often, Africa’s political conflicts are blamed on the “arbitrary” nature of its borders. Products of 19th-century European colonialism, most African national boundaries were drawn with little regard for African communities. Many scholars and policymakers have come to see them as artificial — and uniquely flawed — constructs.

Yet how different are African boundaries from those of countries like the United States? As the historian Rachel St. John notes, the seemingly random line dividing Mexico from the United States was established only in the mid-1800s and remained porous and ill-defined for much of its history. Trump has faced intense criticism for his efforts to limit migration from Mexico, which has already had devastating human consequences. But rarely do we hear the legitimacy of the U.S.-Mexico border called into question in American policy debates.

Africans, however, have long recognized the contested nature of international frontiers. After World War II, African political thinkers called for the dismantling of colonial boundaries. Decades before the European Union was implemented, leaders such as Kwame Nkrumah, Ghana’s first president, advocated for a United States of Africa. Many elites argued that a united Africa would be both politically and economically more viable than a continent of independent nation-states.

Although African territorial borders proved surprisingly resilient during the era of decolonization, they remain to this day subject to much political debate. Recent efforts by the African Union to promote regional integration and create a common passport have been lauded by many as a return to the Pan-Africanist ideals of the 1960s (despite concerns that such policy moves would primarily benefit a mobile elite).

Several political theorists have also invested hope in the idea of a borderless future for the continent. Achille Mbembe argues that rather than disavow “long traditions of circulation that [have] always been the dynamic motor of change in the continent,” African countries should scrap colonial boundaries and allow for freedom of movement across the continent.

Yet some of the most promising alternatives to the legal status quo are being worked out not by policymakers, state officials or political theorists, but by migrants themselves. In northeast Africa, cross-border migration has long been a feature of the daily lives of the Somali population. Not unlike the U.S.-Mexico border, the frontiers between Ethiopia, Kenya, Somalia and other adjoining countries cut across social, economic and political networks that long predate the advent of the modern state.

Throughout the colonial era and into today, Somali nomads, laborers, sailors, soldiers, asylum seekers and traders regularly traversed the boundaries dividing them between different European and African territories. The rallying cry of many Mexican American activists could just as easily apply to Somalis in the region: “We didn’t cross the border; the border crossed us.”

Such forms of mobility have often forced institutional changes or become grounds for imagining alternative political possibilities. In the years after World War II, Pan-Somali nationalists (much like Kurdish nationalists or Pan-Arab proponents) sought to remake colonial boundaries. Their goal of unifying territories across the region into a single state drew directly upon the experiences of the region’s mobile inhabitants. Should a nomad who moves livestock in response to seasonal and ecological changes show deference to a line on a map? Such sentiments were captured by a popular expression in the 1960s: “Wherever the camel goes, that is Somalia.”

The idea of a Greater Somali nation-state, which threatened neighboring African countries, was a product of its time. It reflected the nationalist fervor of the post-World War II era. Nevertheless, the cross-border networks that underpinned this vision remain as relevant as ever. From the late 1980s onward, hundreds of thousands of refugees have relied upon clan and religious ties to escape the violence in Somalia, gain asylum among kin in neighboring countries and circumvent overcrowded refugee camps. Inspired by the comparative success of these “informal” networks, some policymakers are now advocating for urban resettlement in lieu of refugee encampment.

At a time when the Trump administration is closing borders to immigrants from Latin America (many of whom are in fact refugees), African countries have little choice but to cede room to long-standing practices of circulation, hospitality and migration. Indeed, dozens of African countries, including those facing severe economic constraints, have managed to take in labor migrants and asylum seekers from neighboring countries.

As recent episodes of anti-immigrant violence in nations such as South Africa suggest, African countries are not immune from the same kinds of nativist anxieties that wrack the United States and much of the world. Nevertheless, some of the most dynamic and progressive (if imperfect) refugee policies are also being developed in countries like Uganda and Tanzania in response to intra-African migration flows.

The heated dispute surrounding Trump’s border wall makes one thing clear: Migration will be a key factor influencing global politics in the 21st century. Yet public debates in the United States are often shaped by a willful neglect of the messy history of boundary making. As Africa’s porous frontiers make evident, the very distinction between “native” and “foreigner” is a product of political battles that mask long histories of interaction and interdependence.

While the possibility of a borderless world may remain elusive, we would do well to learn from the long-term struggles of African migrants. As their histories indicate, the territorial boundaries we have become accustomed to today are neither timeless nor fixed. And however much we may shore up our borders, our fate will remain intertwined with those living on the other side, whose lives are disrupted by global forces.