Ukrainian troops are probing Russian defenses as spring gives way to a second summer of fighting, and Kyiv's forces are facing an enemy that has made mistakes and suffered setbacks in the 15-month-old war. But analysts say Moscow also has learned from those blunders and improved its weapons and skills.

Russia has built heavily fortified defenses along the 1,000-kilometer (600-mile) front line, honed its electronic weapons to reduce Ukraine's edge in combat drones, and turned heavy bombs from its massive Cold-War-era arsenal into precision-guided gliding munitions capable of striking targets without putting its warplanes at risk.

The latest twist in Donald Trump's attritional war with U.S. law enforcement, as with so much else in the former president's story, throws the United States into unprecedented territory.

Turkish President Recep Tayyip Erdogan, a populist with increasingly authoritarian tendencies, is scheduled to take the oath of office and start his third presidential term Saturday following his latest election win.

Erdogan, who has led Turkey as prime minister or president for 20 years, prevailed in a runoff race last weekend despite the country's ongoing economic crisis and his government's criticized response to a February earthquake that killed more than 50,000 people.

He's heir to the throne in one of the oldest monarchies in the Middle East and a descendant of the Prophet Muhammad. She's a Saudi architect with an aristocratic pedigree of her own.

Crown Prince Al Hussein bin Abdullah II, 28, and Rajwa Alseif, 29, are to be married on Thursday at a palace wedding in Jordan, a Western-allied monarchy that has been a bastion of stability for decades as Middle East turmoil has lapped at its borders.

Turkish President Recep Tayyip Erdogan won reelection in a runoff Sunday, following a nail-biter first round two weeks earlier. Having secured another five years, Erdogan now faces a host of domestic challenges in a deeply divided country, from a battered economy to pressure for the repatriation of Syrian refugees to the need to rebuild after a devastating earthquake.

Here's a look at the challenges ahead.

Tensions between Serbia and Kosovo flared anew this weekend after Kosovo's police raided Serb-dominated areas in the region's north and seized local municipality buildings.

There have been violent clashes between Kosovo's police and local Serbs, leaving several people injured on both sides.

Two opposing visions for Turkey's future are on the ballot when voters return to the polls Sunday for a runoff presidential election that will decide between an increasingly authoritarian incumbent and a challenger who has pledged to restore democracy.

President Recep Tayyip Erdogan, a populist and polarizing leader who has ruled Turkey for 20 years, is well positioned to win after falling just short of victory in the first round of balloting on May 14. He was the top finisher even as the country reels from sky-high inflation and the effects of a devastating earthquake in February.

When Turks head to the polls on Sunday to decide a historic presidential election, the Kremlin will be hoping they give long-standing leader Recep Tayyip Erdogan a convincing victory, observers say.

The winner will have leverage over key areas for Moscow, such as Russia's large-scale military campaign in Ukraine, the war in Syria and the Kremlin's standoff with NATO.

Like the blue and yellow flags that popped up around the U.S. when Russia invaded Ukraine 15 months ago, U.S. popular support for Washington's backing of Ukraine has faded a little but remains widespread, a survey by the University of Chicago's Harris School of Public Policy and NORC shows.

It found that half of the people in the U.S. support the Pentagon's ongoing supply of weapons to Ukraine for its defense against Russian forces. That level is nearly unchanged in the past year, while about a quarter are opposed to sustaining the military lifeline that has now topped $37 billion.

Russia alleges that dozens of Ukrainian militants crossed into one of its border towns in its Belgorod region, striking targets and forcing an evacuation, before over 70 of the attackers were killed or pushed back by what the authorities termed a counterterrorism operation.

Ukraine denied any involvement in the skirmishes Monday and Tuesday, instead blaming two Russian groups that claim to be volunteers fighting alongside Kyiv's forces in an uprising against the government of President Vladimir Putin.