The agreement by five U.S. allies to invest in the U.S. Defense Department’s primary satellite communications system is unqualified good news for all parties involved and validation for the Pentagon’s strategy of enhancing its space capabilities via international cooperation.

Following in the footsteps of Australia, which bought into the Wideband Global Satcom (WGS) system in 2007, Canada, Denmark, Luxembourg, the Netherlands and New Zealand agreed to invest a combined $620 million in a ninth satellite. In return, those countries get immediate access to the entire constellation, which now boasts four satellites on orbit, in proportion to the amount of their individual investment. The U.S. Defense Department, meanwhile, gets an expanded and more robust constellation, better interoperability for coalition operations and a small shot in the arm for an increasingly challenged space industrial base.

Canada is making the biggest non-U.S. investment in WGS-9, at $396.5 million over 20 years. That makes sense given that Canada has a bigger military and works more closely with U.S. forces than the others, and has vast territory to cover. Moreover, WGS prime contractor Boeing has agreed to return nearly $240 million to the Canadian economy in the form of jobs.

Officials representing the new WGS partners said joining the U.S.-led program is cheaper than procuring commercial satellite capacity, especially at spot market prices. But if the U.S. experience is any example, these countries will continue to procure substantial commercial capacity.

With 10 planned satellites and a $10 billion price tag, the WGS constellation is by far the largest international cooperative military space program. It embodies a key tenet of the National Security Space Strategy unveiled a year ago by the administration of U.S. President Barack Obama: seek out partnerships to share and enhance space capabilities at reduced cost.

Currently there are no U.S. plans to bring other countries into the WGS tent, but one can envision similar international arrangements in the future, and not necessarily centered on U.S. satellite systems. America’s allies in Europe, for example, have been deploying increasingly capable optical and radar imaging satellites in recent years.

For a U.S. administration that has had its stumbles in the international space arena, particularly on the civil side, WGS represents a refreshing turn for the better.