The former commander of NATO’s quick reaction force, who is now poised to step into the role as Britain’s army chief, says his country’s troops should be prepared to be engaged in Afghanistan for decades to come.

In an interview with The Times of London, Gen. David Richards forecasted a commitment that will change over time, with increased focus on development, governance and security sector reform.

But while the British army’s role will evolve, “the whole process might take as long as 30 to 40 years,” Richards said during an interview published Saturday.

Richards added that there was “absolutely no chance” of NATO pulling out completely, telling The Times that Britain would continue to do its part in the nation-building effort.

The general’s comments have caused consternation among some British political leaders, who are saying such a commitment is unsustainable.

Meanwhile, at Supreme Headquarters Allied Powers Europe in Belgium a spokesman declined to comment on Richards’ prediction for NATO involvement in Afghanistan.

Richards’ comments, however, are not so different from assessments by U.S. military commanders, who generally shy away from speculating about time lines. Typically, U.S. military officials tend to speak more vaguely, talking instead about “long-term commitments” to the region.

However in January, Gen. John Craddock, supreme allied commander Europe at the time, offered a rough projection, which resembles Richards’ views.

Craddock, who retired last month, told reporters that he expected U.S. troops to be engaged in Afghanistan for at least a decade, if not longer.

“Maybe not at current force levels, but I think we’ll see a presence there for decades,” Craddock said.

Before his recent confirmation, Adm. James Stavridis — Craddock’s replacement — was asked by the Senate Armed Services Committee: “How confident are you that NATO is prepared to sustain its long-term commitment to ISAF (International Security Assistance Force), given the challenging security situation in Afghanistan?”

Without offering a timeline, NATO’s new top military leader answered: “... I am confident that NATO is capable and willing to fulfill and sustain its commitment to ISAF. … The Alliance has given no indication as having any doubt in their decision and I am confident that member nations will stay the course in providing Afghanistan the stability and security it needs to move forward.”