Jim Webb, a Virginia Democrat who was elected to the Senate in 2006 and served a single term, announced on Thursday that he is running for president. Mr. Webb, a Vietnam veteran and former Navy secretary under President Ronald Reagan, has policy positions do not fall neatly along party lines. Here is where he stands on the issues.

Foreign Policy

Mr. Webb has been a persistent critic of the Iraq war, warning in 2002 that “those who are pushing for a unilateral war in Iraq know full well that there is no exit strategy if we invade.” He has also been more critical than the rest of the Democratic field of President Obama’s efforts to reach a deal with Iran to curtail its nuclear program, saying, “The end result of this could well be our acquiescence in allowing Iran to develop a nuclear weapon.” But he has praised Mr. Obama’s approach of using sanctions against Russia for its support of the rebels in Ukraine. And he said Mr. Obama made “the right decision” in recently moving to normalize relations with Cuba.

Same-Sex Marriage

Mr. Webb once opposed same-sex marriage, but he says his views have evolved and he now supports it, calling it “a good thing for this country.”

Environment

Mr. Webb has drawn criticism from Democrats for some of his past positions on the environment. In 2011, he voted in favor of a measure to halt the Environmental Protection Agency’s ability to regulate greenhouse gases. He has also expressed support for the Keystone XL pipeline to take oil from the oil sands of Alberta to the United States, and he has called on President Obama to allow for oil and natural gas exploration off the coastline of Virginia.