In this Sunday’s gospel Jesus asks a pointed question of the disciples of John the Baptist who are following him: "What are you looking for?" Diplomatic observers are worriedly asking the same of Iran as the country continues to challenge the West. Iran sentenced a dual U.S.-Iranian citizen to death Monday, allegedly for spying for the CIA.

When Western governments announced tighter sanctions on the import of Iranian oil in response to that country’s continued development of nuclear enrichment materials, Iran responded by threatening to close the straits of Hormuz, the world’s most important oil shipping route. Further escalating tensions, an Iranian nuclear scientist was killed Wednesday by a car bomb, likely part of a covert war against Iran’s nuclear program.

The sentence against the American, Amir Mirzaei Hekmati, 28, a former U.S. Marine, became a new point of contention and possible bargaining leverage in Iran’s struggle against the West over it nuclear development. A tightening vise of sanctions, which threaten vital oil sales and with them the nation’s economy, has left Tehran feeling besieged and has plunged relations with the United States and its allies to their lowest levels since the 1979 Islamic Revolution.

“This whole case is very politically motivated,” said Hadi Ghaemi, executive director of the International Campaign for Human Rights in Iran, an advocacy group based in New York City that has been monitoring Hekmati’s case. “There’s absolutely no evidence against him.”

Iranian officials accused the U.S. and Israel of being behind the car bomb that killed 32-year-old chemical engineer Mostafa Ahmadi-Roshan. The fifth daylight attack on technical experts in two years, the magnetic bomb delivered a targeted blast to the door of Ahmadi-Roshan's car during Wednesday's morning rush-hour. His driver also died, Iranian media said, and a passerby was slightly hurt.

The assassination comes a day after the head of Israel's military told parliament that 2012 "will be a critical year in the connection between Iran gaining nuclear power, changes in leadership, continuing pressure from the international community, and events that happen unnaturally." It follows other similarly cagey comments from top Israeli officials in recent months as well as remarks from former officials who said foreign intelligence agencies are responsible for the deadly attacks.

"There are countries who impose economic sanctions and there are countries who act in other ways," Israel's Minister of Intelligence and Atomic Energy Dan Meridor said late last year.

Iranian President Mahmoud Ahmadinejad defended his country's nuclear program as he began a four-nation tour of Latin America this week, joining his ally Venezuelan President Hugo Chavez in accusing the U.S. and its allies of using the dispute to unjustly threaten Iran.

Sources: Articles by Ian James for the Associated Press, Rick Gladstone
and Harvey Morris for the New York Times, and Alexander Marquardt for ABC News