The Washington Redskins made a good decision by acquiring former Dallas Cowboys Pro Bowl defensive lineman Jason Hatcher. In one move, the Redskins potentially improved themselves and may have weakened their NFC East division rival, whom Hatcher led with 11 sacks last season. Team decision-makers are counting on Hatcher to help bolster the defense — and Washington’s porous secondary in particular — by improving the pass rush.

By making a four-year, $27.5 million commitment to Hatcher (he will receive $10.5 million guaranteed), Redskins General Manager Bruce Allen showed his determination to upgrade a defensive line that produced only 5¹ / ₂ sacks last fall. During that same span, Hatcher and Redskins outside linebackers Brian Orakpo and Ryan Kerrigan accounted for 29¹ / ₂ sacks.

Redskins defensive coaches, people within the organization say, strongly encouraged management to commit more resources to improve the pass rush. The joke in the organization was that if the Redskins had an elite pass rusher, defensive coordinator Jim Haslett could pick a couple of fans in the stands at FedEx Field to play safety, a position that has been unsettled for years. Based on what he did last season for the Cowboys, Hatcher was among the game’s best at getting to the quarterback.

It wasn’t just that Hatcher led all NFL defensive tackles in sacks. What should excite Redskins fans most is that he recorded double-digit sacks from an interior position in a 4-3 alignment. Hatcher’s eye-opening statistics (half of Hatcher’s total would have been a good year for most players at his position) indicate he has both the strength to beat double-teams and the agility and quickness to win one-on-one battles. That’s a great combination. The Cowboys figure to miss it.

Last season, Hatcher, who also has played end in a 3-4 front similar to the one the Redskins use, was the Cowboys’ most dependable player along a defensive line slowed by injuries. Pro Bowler Anthony Spencer missed all but one game. Perennial all-pro DeMarcus Ware sat out three games and finished with a career-low six sacks.

On Wednesday, the Cowboys released Ware because of salary cap concerns, and he quickly signed with the Denver Broncos. The Cowboys have big holes up front on defense. The Redskins are happy to have opened at least one.

With Hatcher aboard next season, Haslett should expect Washington’s front five — nose tackle, defensive ends and outside linebackers — to consistently pressure opposing quarterbacks, reducing the need to blitz. That, in turn, would enable Haslett to commit more players to coverage. The back end of the Redskins’ defense may need a lot of help.

Although it’s reasonable for the Redskins to envision improvement because their pass rush could be better, cornerback DeAngelo Hall is the only proven impact player in the secondary. Safety, as longtime Redskins linebacker London Fletcher wrote on Twitter the other day, “is a MAJOR concern right now!”

And having a high sack total isn’t a prerequisite to playing well on defense. For example, the Pittsburgh Steelers finished tied for 17th in the league with 35 sacks in 2011. But they led the NFL in total defense, passing defense and ranked eighth against the rush. The best defenses have playmakers along all three levels — on the line, at linebacker and in the defensive backfield. It appears the Redskins’ theory about safeties being less important on a team with a good pass rush will be tested.

Despite Hatcher’s success with the Cowboys, they still had one of the league’s worst defenses last season. Dallas was last in yards per game allowed and ranked 30th out of 32 teams in passing defense. Generally in the NFL, it takes more than one special player on a unit to make an impact on the whole group.

Orakpo hasn’t lived up to his billing as an edge rusher. Still, the Redskins assigned the franchise tag to him, guaranteeing Orakpo at least $11.455 million next season. He needs to make many more plays than he has in the past. Same goes for Ryan Kerrigan, who had only two sacks in Washington’s last nine games. Hatcher has something to prove as well.

There is risk associated with any signing, and the Redskins assumed a lot in acquiring Hatcher. He turns 32 in July, and next season will be his ninth in the league. Generally, teams are reluctant to give 30-plus players long-term deals because of how rapidly most decline physically, “and a lot of times, about halfway through the contract, you’re wishing they were playing for someone else,” Hall of Famer Joe Gibbs once told me.

Hatcher, who became a starter in 2011, hadn’t had as many as five sacks in a season until totaling 11 in a contract year. Was it a career anomaly? Based on the way the Redskins structured his contact, they apparently have concerns. With a $9 million signing bonus and a $1.5 million base salary next season, Hatcher this year will receive all the guaranteed money in the deal. If Hatcher flops, the Redskins won’t owe him anything beyond next season. Of course, they also would have burned $10.5 million.

Six times in the past eight seasons, the Redskins have finished last in the NFC East. They needed to do something in free agency to break that trend. By signing Hatcher, the Redskins may be getting started.