HARI SREENIVASAN: President Obama issued a new warning to Syria today. He left open the possibility of U.S. military involvement if the regime were to deploy chemical or biological weapons in its crackdown on the opposition. Syria is known to possess such weapons. The president acknowledged that any such action would force his administration to reassess its policy.
PRESIDENT BARACK OBAMA: We have put together a range of contingency plans.
We have communicated in no uncertain terms with every player in the region that that's a red line for us and that there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons. That would change my calculations significantly.
HARI SREENIVASAN: In Syria today, heavy shelling rang out across the country, killing up to 30 people. Plumes of thick smoke could be seen rising above the cities of Aleppo, of Daraa, and a suburb of Damascus. Fresh violence erupted in spite of the Muslim holiday marking the end of the holy month of Ramadan.
Meanwhile, U.N. peacekeepers pulled out of Syria a day after their mandate ended. They were tasked with monitoring last April's cease-fire, but the truce never held.
President Obama has spoken to Afghan President Hamid Karzai about a wave of lethal insider attacks on international troops. In the latest attack on Sunday, two Afghan policemen turned their weapons on U.S. troops in Kandahar province, killing one American.
So far in 2012, there have been 32 such attacks, up from 21 for all of last year. President Obama said U.S. officials are hard at work on the problem, but the vetting process for Afghan troops has to be more rigorous.
The wife of a disgraced Chinese politician received a suspended death sentence today for the murder of a British businessman. Gu Kailai is expected to avoid execution in the poisoning death of her business associate Neil Heywood last November, but she will likely serve life in prison.
We have a report from Angus Walker of Independent Television News.
ANGUS WALKER: She has escaped execution. Sentenced to death, suspended for two years, she could be free in 10 years, despite admitting the murder of British business consultant Neil Heywood.
In a personal statement to the court, she claims she had suffered a mental breakdown. It was a show trial which left unanswered questions.
On Chinese social media, many asked if the woman in court, seen here on the left, was in fact her body double. She certainly looks very different to a recent photo of Gu Kailai seen here on the right. But there's no doubt Neil Heywood had a close relationship with Gu Kailai.
ITV News has learned she was godmother to his son, and she once asked him to leave his wife. According to one of his close friends, Neil Heywood had been asking Gu Kailai for money. He had been working as a go-between for the family for many years, involved in business deals. And he felt that he had hadn't been properly paid.
The court heard Neil Heywood was lured to this hotel in the Chinese city of Chongqing last November. There, Gu Kailai poisoned him with cyanide. She claimed he had threatened her son.
Gu's husband, Bo Xilai, was a powerful party boss in the city, now being investigated for corruption. There's a widely held belief that Neil Heywood had been drawn into a darker political plot to stop Bo Xilai becoming one of China's top leaders later this year.
Neil Heywood worked from home in the Chinese capital. His car, complete with 007 number plates, remains outside. The British government insists he wasn't a spy, but his life and death remain shrouded in mystery.
HARI SREENIVASAN: A family aide and four police officers will also serve time in prison for assisting in the murder plot.
In South Africa, striking miners were given until tomorrow to quit striking and return to work. Last week, police shot and killed 34 striking miners outside the platinum mine.
Others were still missing four days after the incident. The workers were originally told they had to come back to work today, or face firing, but Lonmin PLC said only about 30 percent reported for duty.
A new round of lightning strikes sparked more wildfires across the Western U.S. today. Thousands were forced to evacuate, and crews fought to control the blazes. Lightning and dry conditions were also to blame for a fire ignited on Saturday in Northern California.
"NewsHour" correspondent Spencer Michels has this report.
SPENCER MICHELS: Lightning lit the dense tender-dry forests on Saturday.
MAN: Flames on the road on either side. And I looked up and everything was black.
SPENCER MICHELS: Fast-spreading fires hit across Northern Central California, well north of Sacramento.
DANIEL BERLANT, fire information officer: This fire has been a very fast-moving fire due to the fact that conditions are just so dry. The brush, the grass, even the timber is incredibly dry.
SPENCER MICHELS: In Shasta and Tehama counties, thousands of homes are threatened. The Red Cross has set up evacuation centers. One of the new fires, dubbed Ponderosa, started Saturday and covers 15,000 acres. It is only 5 percent contained.
To the west, in Mendocino County, the Pass Fire covers another 5,000 acres. Ten other fires are burning across dry expanses in Northern California. So far this summer throughout the West, 13 states have major fires.
Hard-hit Central Rocky Mountain regions have seen a bit of a reprieve, but this map from the U.S. Forest Service shows an arc from western Montana through Idaho, eastern Washington and Oregon, parts of Nevada and into California continues ablaze amid a brutal fire season.
And this map of drought conditions from the National Oceanographic and Atmospheric Administration shows the severe drought in many of the fire-affected areas.
WOMAN: Everybody is afraid. Our nerves are shot.
SPENCER MICHELS: In Idaho, an 85,000-acre blaze has forced the evacuation of the town of Featherville.
MAN: Are you reading me OK?
SPENCER MICHELS: To the west, in Washington State, crews have gained the upper hand on fires there.
WOMAN: And here's our bed.
SPENCER MICHELS: But some returned home to find everything gone.
WOMAN: It's like a death in the family.
SPENCER MICHELS: So far this summer, more than 6.5 million acres have burned, 10,000 square miles. That's an area the size of Vermont.
HARI SREENIVASAN: On Wall Street today, stocks changed very little. The Dow Jones industrial average lost more than three points to close above 13271. The Nasdaq fell less than a point to close at 3076.
The comedienne and humorist Phyllis Diller died in her sleep today in Los Angeles. Diller was famous for her distinctive cackle and for paving the way for women in the world of stand-up comedy.
She didn't get into comedy until she was nearly 40, after she'd been married and had five children. She worked well into her '80s, performing in nightclubs, films, and on TV.
Her routine often poked fun at her looks and her life as a housewife. Phyllis Diller was 95 years old.
The film director Tony Scott committed suicide in Los Angeles by jumping from a bridge. The British-born director first rose to fame with the 1986 blockbuster "Top Gun."
In all, he directed 16 films, mostly action and thrillers. Scott's death was under investigation as a suicide. Authorities said he left several notes to loved ones behind. Tony Scott was 68 years old.
Those are some of the day's major stories.