• Feds viewed state computers as back door for hackers

WASHINGTON - As the Obama administration raced to meet its self-imposed deadline for online health insurance markets, security experts working for the government worried that state computer systems could become a back door for hackers.

Documents provided to The Associated Press show that more than two-thirds of state systems that were supposed to tap into federal computers to verify sensitive personal information for coverage were initially rated as "high risk" for security problems.

Back-door attacks have been in the news, since the hackers who stole millions of customers' credit and debit card numbers from Target are believed to have gained access through a contractor's network.

• Obama tells Pentagon to map possible full Afghan pullout

WASHINGTON - In a blunt warning to Afghan President Hamid Karzai, President Barack Obama threatened on Tuesday to withdraw all U.S. troops from Afghanistan by the end of this year if a crucial security pact isn't signed - and he ordered the Pentagon to accelerate planning for just that scenario.

At the same time, in a rare phone call with Karzai, Obama indicated he was willing to wait his mercurial counterpart out and sign a security agreement with a new Afghan president after April elections. That would allow the U.S. to keep as many as 10,000 troops in the country.

The effort seemed aimed at marginalizing Karzai's role in the high-stakes negotiations over the future of the lengthy American-led war.

"We will leave open the possibility of concluding a (security agreement) with Afghanistan later this year," the White House said in a statement following the call. "However, the longer we go without a (deal), the more challenging it will be to plan and execute any U.S. mission."

Obama's attempt to minimize Karzai's importance to U.S. decision-making underscores how fractured the relationship between the two leaders has become. Tuesday's phone call was the first direct contact between Obama and Karzai since last June. The Afghan leader has deeply irritated Washington with anti-American rhetoric, as well as with his decision this month to release 65 prisoners over the objections of U.S. officials.

• Government study says preschooler obesity is falling

ATLANTA - Toddler obesity shrank sharply in the past decade, a new study suggests. While promising, it's not proof that the nation has turned a corner in the battle against childhood obesity, some experts say.

The finding comes from a government study considered a gold-standard gauge of trends in the public's health. The researchers found that obesity among children ages 2 to 5 decreased - to 8 percent, from 14 percent a decade ago. That would represent a 43 percent drop.

But the only decline was seen in preschoolers, not in older children. And some experts note that even the improvement in toddlers wasn't a steady decline, and say it's hard to know yet whether preschooler weight figures are permanently curving down or merely jumping around.

• Crimea rally decries 'bandits' in Kiev forming new government

SEVASTOPOL, Ukraine - Dozens of pro-Russian protesters rallied Tuesday in this Crimean Peninsula city, bitterly denouncing politicians in Kiev who are trying to form a new government, with some even calling for secession from Ukraine. A Russian lawmaker stoked their passions by promising that Moscow will protect them.

"Russia, save us!" they chanted.

The outburst of pro-Russian sentiment in the strategic peninsula on the Black Sea, home to a Russian naval base, came amid fears of economic collapse for Ukraine as the fractious foes of President Viktor Yanukovych failed to reach agreement on forming a new national government and said the task of assigning posts could not be completed before Thursday.

While Ukraine's politicians struggled to reorganize themselves in Kiev, a Russian flag had replaced the Ukrainian flag in front of the city council building in Sevastopol, 500 miles to the south of the capital. An armored personnel carrier and two trucks full of Russian troops made a rare appearance on the streets, vividly demonstrating Russian power in this port city where the Kremlin's Black Sea Fleet is based.

• Mexico determined to keep Guzman in custody

MEXICO CITY - Mexico made clear Tuesday it is determined to keep Joaquin "El Chapo" Guzman in its highest-security prison for the foreseeable future, putting off U.S. extradition in a move that could bolster President Enrique Pena Nieto's nationalist credentials but also shine a spotlight on the country's woeful judicial system.

Experts say Pena Nieto's administration and those of his predecessors have proven unable to match headline-grabbing arrests like Guzman's with complex, long-term investigations and prosecutions of deep-rooted criminal networks. Cases have stalled and cartels have continued to operate.

Last year, one of Guzman's closest allies walked out of the prison where the U.S. said he was running drugs from behind bars.

The Mexican government says there is no way Guzman will repeat the 2001 escape that let him roam western Mexico for 13 years as he moved billions of dollars of cocaine, methamphetamine and heroin around the world. Authorities here say they want to be the first to interrogate Guzman, and use the information to dismantle his Sinaloa cartel, a multibillion-dollar enterprise that dominates drug trafficking in much of Mexico and stretches into 54 countries.

Two federal judges ruled Tuesday that Guzman will have to stand trial on separate drug-trafficking and organized-crime charges in Mexico. And the Pena Nieto administration said the man widely considered the world's most-powerful drug lord until his capture Saturday will face at least six other pending criminal cases before it even considers extraditing him to the U.S.

"I don't think it's going to happen anytime soon," Attorney General Jesus Murillo Karam said in a radio interview. "This is the start of a full investigation that will allow us to fully eradicate his organization. It would be pointless to do anything else."