Ukraine must decide how its Russian incursion ends — advance further or retreat before it's too late

More than a week into Ukraine's surprise incursion into Russia's Kursk region and the operation, and the gains made in the last week are likely to have exceeded even Kyiv's wildest expectations.

Ukrainian forces now occupy more than 1,000 square kilometers of Russian territory and have captured 74 settlements, Ukraine's top military commander Oleksandr Syrskyi told Ukrainian President Volodymyr Zelenskyy Tuesday.

On Wednesday, the president claimed Ukraine's forces had advanced even further into Russia, making gains of 1-2 kilometers and capturing more than 100 Russian soldiers since the beginning of the day.

Ukraine appeared to make the most of its newfound offensive momentum by launching the largest ever drone attack yet on Russian military airfields on Thursday, destroying a Russian Su-34 jet used to launch glide bombs at Ukrainian front-line positions and cities, Ukraine's General Staff said. CNBC was unable to independently verify the claims made by Zelenskyy or the military.

Russia is seething about the incursion which has seen the first foreign army on Russia soil since World War II. It says the raid is designed to stop its rolling offensive in eastern Ukraine, and to destabilize the country. Officials in Moscow have also used the incursion to further attack Ukraine's Western backers.

A grim-faced President Vladimir Putin has vowed a "worthy" retaliation to what he initially described as a "large-scale provocation." But the gains in the southwestern region of Kursk have seemingly stunned Russia's military command, which has yet to mount a robust response to the incursion.

Geopolitical and defense analysts warn that a response will come, and while Kyiv can bask in the success of its cross-border operation for now, it