Mitt Romney intensified his efforts Monday to draw a sharp contrast with President Obama on national security in the presidential campaign’s closing stages, portraying Mr. Obama as having mishandled the tumult in the Arab world and having left the nation exposed to a terrorist attack in Libya.

In a speech he gave at the Virginia Military Institute, Mr. Romney declared that “hope is not a strategy” for dealing with the rise of Islamist governments in the Middle East or an Iran racing toward the capability to build a nuclear weapon, according to excerpts released by his campaign.

The essence of Mr. Romney’s argument is that he would take the United States back to an earlier era, one that would result, as his young foreign policy director, Alex Wong, told reporters on Sunday, in “the restoration of a strategy that served us well for 70 years.”

But beyond his critique of Mr. Obama as failing to project American strength abroad, Mr. Romney has yet to fill in many of the details of how he would conduct policy toward the rest of the world, or to resolve deep ideological rifts within the Republican Party and his own foreign policy team. It is a disparate and politely fractious team of advisers that includes warring tribes of neoconservatives, traditional strong-defense conservatives and a band of self-described “realists” who believe there are limits to the degree the United States can impose its will.

Each group is vying to shape Mr. Romney’s views, usually through policy papers that many of the advisers wonder if he is reading. Indeed, in a campaign that has been so intensely focused on economic issues, some of these advisers, in interviews over the past two weeks in which most insisted on anonymity, say they have engaged with him so little on issues of national security that they are uncertain what camp he would fall into, and are uncertain themselves about how he would govern.

“Would he take the lead in bombing Iran if the mullahs were getting too close to a bomb, or just back up the Israelis?” one of his senior advisers asked last week. “Would he push for peace with the Palestinians, or just live with the status quo? He’s left himself a lot of wiggle room.”

In his remarks, Mr. Romney addressed the Palestinian issue, saying, “I will recommit America to the goal of a democratic, prosperous Palestinian state living side by side in peace and security with the Jewish state of Israel.” And he faulted Mr. Obama for failing to deliver on that front.

But while the theme Mr. Romney hit the hardest in his speech at V.M.I. — that the Obama era has been one marked by “weakness” and the abandonment of allies — has political appeal, the specific descriptions of what Mr. Romney would do, on issues like drawing red lines forIran’s nuclear program and threatening to cut off military aid to difficult allies like Pakistan or Egypt if they veer away from American interests, sound at times quite close to Mr. Obama’s approach.

And the speech appeared to glide past positions Mr. Romney himself took more than a year ago, when he voiced opposition to expanding the intervention in Libya to hunt down Col. Muammar el-Qaddafi with what he termed insufficient resources. He called it “mission creep and mission muddle,” though within months Mr. Qaddafi was gone. And last spring, Mr. Romney was caught on tape telling donors he believed there was “just no way” a two-state solution to the Israeli-Palestinian conflict could work.

Mr. Romney’s Monday speech called vaguely for support of Libya’s “efforts to forge a lasting government” and to pursue the “terrorists who attacked our consulate in Benghazi and killed Americans.” And he said he would “recommit America to the goal of a democratic, prosperous Palestinian state living side by side in peace and security” with Israel. But he did not say what resources he would devote to those tasks.