South Korea will buy 40 Lockheed Martin F-35As to satisfy a fighter requirement initially set at 60 aircraft, its joint chiefs of staff announced on Nov. 22. A further 20 fighters, not necessarily F-35s, may be ordered later, subject to security and fiscal circumstances.

The decision almost certainly puts an end to Boeing’s hopes of selling more F-15s to South Korea. The other competitor, the Eurofighter consortium, led by EADS in South Korea, seems to have a remote chance of filling the later order.

By deciding on only 40 F-35s for the F-X Phase 3 requirement, South Korea has resolved a conflict between the air force’s desire for a highly stealthy aircraft, its need to replace old fighters quickly, and its limited budget of 8.3 trillion won ($7.2 billion). The solution was to defer part of the order.

Industry officials think 40 F-35s, bought in the U.S. government’s Foreign Military Sales process, will not use up the entire budget. The South Korean air force tends to buy fighters in multiples of 20, which explains why more than 40 are not planned.

Lockheed Martin is expected to deliver the aircraft over four years beginning in 2018. The further 20 would immediately follow.

The air force effectively chose the F-35 about two weeks ago when, according to local media reports, it set a numerical requirement for radar cross-section. This followed the derailment of the original competition in August, when it was revealed that only Boeing could meet the budget. Instead of completing the competition in the usual way by giving the order to that company, the government decided instead that it would review its requirements, budget and process.

The great bulk of air force opinion has always seen the F-35 as the desirable aircraft, according to South Korean government officials, even though the chief of the air force at the last minute was willing to take F-15s to get new fighters into service without further delay.

F-X Phase 3 has been aimed at replacing old and increasingly ineffective F-4 Phantoms and F-5 Tigers. Under phases 1 and 2 last decade, South Korea ordered 61 F-15s, including a replacement for one that crashed.

“The F-35A will be used as a strategic weapon to gain a competitive edge and defeat the enemy in the early stage of war,” Yonhap news agency quotes the spokesman for the joint chiefs of staff, Eom Hyo-sik, as saying. “The South Korean military also will use the aircraft to effectively deal with provocations.”

For the additional 20 aircraft, if they are ordered, the requirements will be reconsidered, he adds. But if they are not, presumably there will be no competition for the F-35 in that later order.

There may be no competition anyway. For the F-X Phase 2 order, only Boeing bid, since every other prospective supplier decided that the air force would certainly want to add more aircraft of the type that had been ordered under Phase 1.

In the same meeting on Nov. 22, the chiefs endorsed the KF-X indigenous fighter program for the mid-term defense budget plan. That does not assure its survival, however. The fiscally and technically challenging KF-program faces great political opposition and is expected to get 2014 funding that will cover only further design studies.

The military wants KF-X development completed by 2020, with deployment from 2023, Yonhap says, citing unnamed officials. The three-year gap between the completion of development and beginning of deployment is not explained, but 2020 is not a realistic date for getting the aircraft ready for service anyway. According to the program schedule, the aircraft would fly for the first time seven years after the launch of full-scale development, which cannot now happen until 2015.