Jeff Monken, talking by phone Tuesday moments after making one of the biggest decisions of his life, called his choice to take the head football coaching position at Army, “one I agonized over because I love Georgia Southern.”

Monken leaves Georgia Southern after accumulating a 38-16 mark in four years and inherits a challenge of turning around an Army program that has had just one winning season since 1996.

“When a four-star general looks you in the eye and says you can make a difference, it’s hard to say no,” joked Monken, later Tuesday afternoon.

But there was no joking about the difficulty to leave Southern where he first worked for five years as an assistant coach under current Georgia Tech coach Paul Johnson, helping the Eagles win two national championships (1999 and 2000). Monken was an assistant when Johnson turned around programs at Navy and Georgia Tech as well. He followed Johnson from Navy to Tech where he spent two years as an assistant before taking the Georgia Southern job.

Monken leaves with a bang, ending the 2013 regular season with a 26-20 victory over Florida, Southern’s first win over a Football Bowl Subdivision school.

“It was terribly difficult (decision), Georgia Southern is a special place,” Monken said. “But (Army) is a special place too, a tremendous opportunity and one I’m excited about.”

Monken’s departure leaves GSU with a big hole in the football program at a very inopportune time. The Eagles are in the middle of recruiting — the next three weeks, however, is a dead period — and their search for an even greater number of top players is paramount this year because the school is moving from the 63-scholarship Football Championship Subdivision to the 85-scholarship Football Bowl Subdivision.

Monken said the decision to take particular assistants with him to West Point still hasn’t been worked out.

At a press conference at Paulson Stadium on Tuesday afternoon, GSU athletics director Tom Kleinlein said he would begin a national search immediately to find the best candidate for the Eagles job.

Some potential candidates for the vacant position are former Georgia Tech and Buffalo Bills assistant Giff Smith (a former All-America defensive end for Southern 1987-1990), Vanderbilt co-defensive coordinator Brent Pry, GSU’s current offensive coordinator Brent Davis and quarterbacks coach Mitch Ware.

Monken took over a program that had accumulated a 21-23 mark during the previous four years. After the 2009 season, coach Chris Hatcher was fired.

Monken immediately re-installed the triple-option offense that had worked so well for the school in the past.

In Monken’s first season, GSU jumped from five wins to 10, including a key regular-season win over No. 1 Appalachian State, before making a run to the FCS semifinals.

The Eagles won Southern Conference championships the next two seasons under Monken. In 2011, he was the league’s coach of the year.

In 2012, Southern led defending champion North Dakota State in Fargo, N.D., with about three minutes remaining before losing.

Monken’s leadership abilities, triple-option background and unique passion for the academies made an impression.

“There was tremendous interest in the position nationally and we felt there were several very qualified candidates, but throughout the process Jeff separated himself from the others,” said Army athletics director Boo Corrigan in a press release. “His passion, energy and strong experience in turning around a program immediately helped him rise to the top of our list.”

The Army coaching job opened Dec. 15 after Rick Ellerson was fired. The Black Knight concluded their season losing to Navy 34-7 – their 12th straight loss to the Middies – and finishing with a 3-9 season.

The job was just too good to pass up, said Monken, who applied for the same position in 2008.

Tuesday, even the leader of Eagle Nation seemed to understand.

“We weren’t in a position to compete with the once in a lifetime opportunity Army presented (to Monken) at this time,” GSU president Brooks Keel said. “Give us five years and we’ll be there.”