Because the best way to project power is to fly under the radar.

On a windswept summer’s evening on Ireland’s Atlantic coast, a heavy rain beats down on Shannon airport’s empty runway. The last scheduled flight of the day departed hours earlier, and the terminal is ghostly quiet. But at the western end of the building, the engines of a chartered Omni Air International plane are starting up. In its cabin, the shapes of people moving — young American servicemen and women — can be seen. The plane is one of hundreds to have transported U.S. troops to and from war zones in the Middle East through this isolated airport. What’s more:

SINCE 2002, MORE THAN 2.5 MILLION TROOPS HAVE PASSED THROUGH SHANNON AIRPORT.

These figures have been discovered because of the work of Shannonwatch, an Irish antiwar group that has monitored the American military’s use of the civilian airport for a decade. A Freedom of Information Act request that it made to the Irish government found that last year at least 730 U.S. military flights stopped at the airport — the highest in 10 years. Donald Trump’s recent announcement that a new strategy for the war in Afghanistan is in the offing means that Shannon’s strategic role is set to grow further still.

“What makes Shannon important is its relative location. It’s a midpoint between the Middle East and North America,” says Anthony Rosello, an expert at the RAND Corporation, a Washington, D.C.–based global policy think tank.

Not everyone in Ireland is extending a céad míle fáilte (a hundred thousand welcomes) to the U.S. military.

Among the planes recorded as having touched down in Shannon last year include 100 C-130 Hercules planes, 15 aircraft identified as either C-17 Globemaster or C-5 Galaxy transporters and, interestingly, 71 executive jets. Half were operated by the U.S. Air Force, Navy or Marines; the remainder by charter airlines such as Omni Air International.

According to Shannonwatch, 22 aircraft suspected of being used for controversial rendition flights have landed at Shannon airport, a policy the Irish government, in theory, opposes. And clearly not everyone in Ireland is extending a céad míle fáilte (a hundred thousand welcomes) to the U.S. military: The airport has become a lightning rod for controversy because of its role in assisting America’s wars. A RED C survey commissioned last year on behalf of Mick Wallace, a member of Ireland’s parliament, found that six out of 10 people oppose the use of the airport by the United States for military-transit purposes.

Public trust in what the U.S. and Irish governments are up to hasn’t been helped by activists’ eagle-eye monitoring. The landing of an armed military plane at Shannon in October 2013 was down to an “administrative error,” according to the U.S. embassy in Dublin. “The situation is bizarre,” says John Lannon of Shannonwatch. “They claim no weapons are being carried.” (Ireland has officially taken a neutral position in international conflicts and affairs since the 1930s.)

The Irish government has also been accused of turning a blind eye to the U.S. military’s pit-stopping at Shannon in part because the agreement was, after deducting local police fees, worth almost $8 million last year alone. Since 2002, the military has paid Ireland around $50 million, money that has helped keep afloat an airport that suffered a two-thirds fall in civilian passenger traffic during the depths of a nationwide recession.

Cash or neutrality? That’s a conundrum the Irish people and government are struggling with. And it’s one not likely to be solved anytime soon, if Mr. Trump’s plans for Afghanistan are borne out.