Questions and answers on US sanctions of Myanmar

YANGON, Myanmar (AP) -- The United States is unwinding two decades of sanctions against Myanmar, as the country's reformist leadership oversees rapid-fire economic and political change. President Barack Obama's visit this week, the first by a serving U.S. president, is a sign of how far relations have come. But Washington continues to take a calibrated approach to easing sanctions, keen to retain leverage should Myanmar's reform momentum stall.

Here's a look at key elements of U.S. sanctions against Myanmar.

Why did the U.S. sanction Myanmar in the first place?

— Washington first enacted sanctions in September 1988, the month after Myanmar's military junta cracked down on peaceful protests, killing thousands. The U.S. responded to deepening human rights violations and brutal suppression of the democratic opposition by tightening sanctions.

Why has the U.S. eased sanctions?

— U.S. policy began to change after Myanmar's president, Thein Sein, took office in March 2011. As the new government released political prisoners, signed cease-fires with ethnic rebels, opened the economy and held elections that saw opposition leader Aung San Suu Kyi take a seat in Parliament, the U.S. normalized diplomatic relations and suspended most major sanctions.

What did the U.S. sanction and which sanctions are still in force?

— Washington banned new investment, financial services, multilateral assistance, and imports. It also barred officials from getting U.S. visas and forbade deals with "crony" businessmen linked to the old regime. Restrictions on most new investment, financial services, multilateral assistance, and most imports from Myanmar have been suspended. The biggest remaining block is the list of "specially designated nationals" and companies that U.S. firms are barred from doing business with because of their alleged links to oppression and corrupt practices.

Why hasn't Washington simply done away with sanctions?

— Washington has taken a carrot and stick approach to retain leverage and reinforce good business practices. Also, they're technically hard to undo. Sanctions are governed by six federal laws and a series of executive orders, often with overlapping provisions. There are also functional bans which require specific benchmarks to be met before certain strictures are eased such as ending the use of child soldiers before arms sales are allowed.

Did sanctions work?

— The jury is out. Advocates point to change in Myanmar as evidence that sanctions encouraged reform. But a large chorus of critics says domestic factors rather than sanctions — which had little effect for two decades — are the real reason for Myanmar's spring. Critics also say sanctions have been too blunt, hurting the corrupt elite less than the common man.