If geopolitics could be compared to a grade school playground, the United Kingdom has long been America’s best buddy. Our two militaries have worked side by side in countless conflicts and likely will continue to do so for years to come. So when the Royal Navy loses one of its most important offensive and defensive capabilities in one fell swoop, we should stand up and take notice.

For years now, the Royal Navy has been armed with American-made Harpoon anti-ship missiles. These missiles provide each vessel with a powerful method of engaging other warships even before they appear on the horizon. With an effective range of 80 miles, these ship-fired missiles can deliver a 488-pound high-explosive warhead directly into the hull of an enemy vessel. Battle tested against Iranian and Libyan navies in the 1980s, the Harpoon has become a staple of the Royal Navy’s warfighting capabilities. That is, until now.

The missiles the U.K.’s Navy currently has in service are set to expire in 2018. Current naval expenditures don’t account for funding a replacement, which will leave the British Navy without any other means of engaging enemy ships besides their 4.5-inch deck guns. These British-made semi-automatic guns aren’t to be dismissed, with their high-explosive rounds, limited personnel requirements, and range of 17 miles, but when compared to the effective range of the Harpoon missiles they’ll have to replace, they leave a 63-mile gap in the radius of each ship’s former offensive and defensive strike capabilities.

This news comes only months after Russia announced that their new anti-ship missiles, capable of hypersonic speeds and a range of 180 nautical miles, will go into production in 2018, the very same year the Queen will find herself without a single anti-ship missile in her fleet’s arsenal. Seventeen miles is a significant range to be able to fire explosive rounds, but the likelihood of naval battles being carried out in such a manner as to actually be able to use these guns grows less likely as each nation’s naval technology continues to advance. The days of broadsiding your opponent with a flurry of cannonballs has long been left behind, in exchange for satellite-guided missiles with fire-and-forget capabilities.