Greater Ukraine or United Ukraine (Соборна Україна Soborna Ukraina) refers to an irredentist concept of the territory claimed by some Ukrainian nationalist

Ukrainian nationalism

Ukrainian nationalism refers to the Ukrainian version of nationalism.Although the current Ukrainian state emerged fairly recently, some historians, such as Mykhailo Hrushevskyi, Orest Subtelny and Paul Magosci have cited the medieval state of Kievan Rus' as an early precedents of specifically...

 groups outside the Republic of Ukraine which are considered part of national homeland by Ukrainians, based on the present-day or historical presence of Ukrainian populations in those areas.

Rise of nationalism

The 10 commandments of the Ukrainian People's Party (1902-1907) were developed by Ukrainian nationalist, the leader of UPP Mykola Mikhnovsky in 1904.
These commandments were kind of honor code for the party. They called for a one, united, indivisible, from the Carpathians to the Caucasus, independent, free, democratic Ukraine - a republic of working people.

Claimed regions

Since Mikhnovsky the idea of ‘Ukrainian Independent United State’ ( Ukrainska Samosiyna Soborna Derzhava) has been a key nationalist slogan, but many would argue that the ‘unification’ (соборність sobornist’) of Ukrainian lands was partially completed in 1939-45.

Today’s would-be Ukraina irredenta is mainly in the east, on the territory that is now part of   Russian Federation:

• Starodub
  Starodub
  Starodub is a town and the administrative center of Starodubsky District of Bryansk Oblast, Russia. It is located on the Babinets River , southwest of Bryansk. Population: 16,000 .-History:...
  
   region north of Chenrihiv
• the south-eastern parts of Voronezh
  Voronezh Oblast
  Voronezh Oblast is a federal subject of Russia . It was established on June 13, 1934.-Main rivers:*Don*Voronezh*Bityug*Khopyor-Economy:...
  
  
• Kursk
  Kursk Oblast
  Kursk Oblast is a federal subject of Russia . Its administrative center is the city of Kursk.-Geography:The oblast occupies the southern slopes of the middle-Russian plateau, and its average elevation is from 177 to 225 meters . The surface is hilly, and intersected by ravines...
  
   and Rostov
  Rostov Oblast
  Rostov Oblast is a federal subject of Russia , located in the Southern Federal District. Rostov Oblast has an area of and a population of making it the sixth most populous federal subject in Russia...
  
   oblasts
• Kuban
  Kuban
  Kuban is a geographic region of Southern Russia surrounding the Kuban River, on the Black Sea between the Don Steppe, Volga Delta and the Caucasus...
  
   region

In the west, some radical nationalists would also covert the following territories:

• left bank of river Dniester in Moldova ( Transnistria (de facto) / western  Moldova (de jure))
• north-eastern  Slovakia: Prešov region
  Prešov Region
  The Prešov Region is one of the eight Slovak administrative regions. It consists of 13 districts.-Geography:It is located in north-eastern Slovakia and has an area of 8,975 km². The region has diverse types of landscapes occurring in Slovakia, but mostly highlands and hilly lands dominate the...
  
  
• south-eastern  Poland: Chełm and Przemyśl
  Przemysl
  Przemyśl is a city in south-eastern Poland with 66,756 inhabitants, as of June 2009. In 1999, it became part of the Podkarpackie Voivodeship; it was previously the capital of Przemyśl Voivodeship....
  
   territories
• south-western  Belarus: Brest region
• northern  Kingdom of Romania: southern Bukovina
  Bukovina
  Bukovina is a historical region on the northern slopes of the northeastern Carpathian Mountains and the adjoining plains.-Name:The name Bukovina came into official use in 1775 with the region's annexation from the Principality of Moldavia to the possessions of the Habsburg Monarchy, which became...
  
   and the area around Maramureș
  Maramures County
  Maramureș is a county of Romania, in the Maramureș region. The county seat is Baia Mare.- History :* The 10th century frontier county of Borsova was founded by Stephen I of Hungary. Since then Máramaros served as the north-eastern border of the Hungarian Kingdom until 1920, the Trianon Peace...
  
  

The possibility of Ukraine making serious territorial pretensions against its neighbors can be discounted (the boot is more likely to be on the other foot). Nevertheless, more radical Ukrainian nationalists may well attempt to take advantage of Russian difficulties in troubled regions such as the north Caucasus

North Caucasus

The North Caucasus is the northern part of the Caucasus region between the Black and Caspian Seas and within European Russia. The term is also used as a synonym for the North Caucasus economic region of Russia....

, and perhaps even further afield, particularly if any serious conflict should develop between Russia and Ukraine.

Kuban

Ukrainians first settled the Kuban

Kuban

Kuban is a geographic region of Southern Russia surrounding the Kuban River, on the Black Sea between the Don Steppe, Volga Delta and the Caucasus...

 in 1792 and until the mid-twentieth century the majority of the population there identified themselves as Little Russia

Little Russia

Little Russia , sometimes Little or Lesser Rus’ , is a historical political and geographical term in the Russian language referring to most of the territory of modern-day Ukraine before the 20th century. It is similar to the Polish term Małopolska of the Polish-Lithuanian Commonwealth...

ns or Ukrainians

Ukrainians

Ukrainians are an East Slavic ethnic group native to Ukraine, which is the sixth-largest nation in Europe. The Constitution of Ukraine applies the term 'Ukrainians' to all its citizens...

. Due to adverse Russian and Soviet national policies, including the Holodomor

Holodomor

The Holodomor was a man-made famine in the Ukrainian SSR between 1932 and 1933. During the famine, which is also known as the "terror-famine in Ukraine" and "famine-genocide in Ukraine", millions of Ukrainians died of starvation in a peacetime catastrophe unprecedented in the history of...

, most of the population adopted a Russian self-identification, and the percentage of those who identified themselves as Ukrainians dropped from an official 55% (1926) to 0.9% (2002).