Russia attacked Sweden in July 1656, while its forces were deeply involved in Poland. That war ended in status quo two years later, but it complicated matters for Khmelnytsky, as his ally was now fighting his overlord. In addition to diplomatic tensions between the tsar and Khmelnytsky, a number of other disagreements between the two surfaced. In particular, they concerned Russian officials' interference in the finances of the Cossack Hetmanate and in the newly captured Belarus. The tsar concluded a separate treaty with the Poles in Vilnius in 1656. The Hetman's emissaries were not even allowed to attend the negotiations.