If Barack Obama was elected on a wave of optimism, eight years later, hopes of a post-racial America have soured amid recognition that it takes more than a black president to overcome centuries of racism.

A recent poll confirmed findings of a number of studies published in the final months of the Obama administration: 52 percent of Americans questioned by Gallup said the country had taken a step backwards on issues of race. Just 25 percent thought things had improved since 2009.

An international conference being held in Paris on Sunday is the latest of many bids to forge peace between Israel and the Palestinians.

Representatives from around 70 nations are to meet in Paris on Sunday to try to chart a course toward restarting moribund Israeli-Palestinian negotiations.

Nearly two months into the assault, Turkey has become bogged down in an unexpectedly bloody fight to retake the Islamic State group's last stronghold in northern Syria. It has been forced to pour in troops, take the lead in the battle from its Syrian allies and reach out to Russia for aerial support.

The fight for al-Bab underscores the precarious path Ankara is treading with its foray in to Syria, aimed against both IS militants and Syrian Kurdish fighters. The assault on the town had already driven a wedge between Turkey and the United States, and now the realignment toward Moscow — which supports the government in Syria's civil war — further tests Ankara's alliance both with Washington and with the Syrian opposition.

As Barack Obama prepares to leave office on January 20, here are nine things his presidency may be remembered for:

- Making history -

Stung by years of failure to stop Syria's bloodshed, the United States is now but a bystander to the civil war as President Barack Obama leaves office.

Secretary of State John Kerry still is speaking sporadically with Russian, Turkish and Arab foreign ministers about cease-fire efforts, and there are occasional consultations with the opposition. But less than two weeks before Donald Trump's presidency begins, the outgoing administration is no longer even claiming to play the leading part in the peace mediation that it spearheaded unsuccessfully for years. Formal contacts with Russia and others in Geneva, the main meeting point for the U.S.-led diplomacy, have ended.

U.S. Gulf allies are looking at Donald Trump to tilt Washington in their favour, analysts say, but fear a dangerous void if the incoming president goes so far as to tear up the Iran nuclear deal.

The U.S. and Russia have become embroiled in a Cold-War-style diplomatic spat over alleged cyberattacks Washington believes were carried out by Moscow in an attempt to skew the U.S. election.

The decades-old Israel-Palestinian conflict has returned to the spotlight after a U.N. resolution condemning Israeli settlements and a major speech by U.S. Secretary of State John Kerry.

Midnight means lights out in Syria's Aleppo: as the clock strikes 12, overworked power generators shut off across the city, plunging war-ravaged neighbourhoods and heritage sites into darkness.