President-elect Obama’s decision to ask current Secretary of Defense Robert Gates to stay on at the Pentagon makes plenty of sense. Critics of Bush administration policies (led, of course, by Mr. Obama himself) have no more reason for frustration at this choice than right-wingers have for jubilation.

Mr. Gates is hardly the sort of hawk he replaced when Donald Rumsfeld resigned after Democrats won the 2006 congressional elections. That election was as much a referendum on the Iraq war as this year’s election was not. And Iraq had slipped as an issue in this year’s presidential campaign well before the financial crisis kicked every other issue aside.

Iraq was almost a non-issue by November because the surge ordered by President Bush and supported by Mr. Gates has been so successful, both militarily and in political reconciliation in Iraq. Candidate Obama’s 16-month withdrawal strategy now looks as if it could fit within the parameters of Mr. Bush’s longstanding conditions-based withdrawal.

In any event, transferring emphasis from Iraq to Afghanistan will require the sort of immensely experienced and savvy administrative capacity that Mr. Gates has displayed at the Pentagon and before that at the CIA and the National Security Council.

In spite of the ambitious democracy agenda of President Bush’s second inaugural address, his second term reflected more realism in using the military to push democracy abroad. The cost of the Iraq mission and the current financial crisis only heighten the restraints on U.S. power projection. The emphasis on diplomacy has already increased. But Mr. Obama’s retention of an experienced hand suggests recognition that “soft power” — the negotiations and the economic power he emphasized in the campaign — cannot be very effective without the threat of hard military power.

In this regard, Mr. Gates at the Pentagon may fit better with Sen. Hillary Clinton at the State Department than Mr. Rumsfeld fit with Gen. Colin Powell at State in Mr. Bush’s first term. Military policy serves foreign policy, and not the reverse, which is why secretaries of state are ahead of secretaries of defense in Cabinet rank.

And military policy does not just reach around the world — it reaches into all 50 American states, as part of what President Eisenhower called the “military-industrial complex.” Keeping Mr. Gates on at the Pentagon should help Mr. Obama reform military-procurement policies that have turned many Pentagon contracts into “cost-plus” boondoggles.

Mr. Gates’s firmness in sacking Army leaders responsible for the scandal of poor care for wounded Iraq war veterans at Walter Reed Army Medical Center may be another reason he was retained.

With the focus now on the economy, the president-elect’s evident concern that defense policy emphasize continuity rather than change, at least for now, should ultimately let him maintain what has been strong in his predecessor’s defense policy, and change what has been weak.

Keeping Robert Gates reinforces our confidence that Barack Obama knows that protecting America is his most important job.