( CNN ) -- Recent developments off the coast of Sweden raise many questions , and we do not as yet have answers . Last week , Swedish media reported that the country 's military was searching for an underwater vessel , possibly a Russian submarine , after an emergency radio transmission allegedly made in Russian ( although Russia has denied it has any vessels in Swedish waters ) . Now , as the Swedish Navy continues to search for the unidentified undersea vessel that may have penetrated the country 's territorial waters , it 's worth keeping in mind some key facts to help place the issue in perspective . For a start , anti-submarine warfare is complex and very difficult to execute properly . Especially in the close confines of territorial waters , the advantages tend to accrue to the submarine . The rocky floor of an inland sea like the Baltic can mask acoustic signatures that give watching ships , helicopters and maritime patrol aircraft the ability to track and identify a subsurface contact . Second , this is happening against the backdrop of the Swedish Navy and Air Force having suffered significant budget cuts over the past decades . As a general proposition , the Swedes have a capable and professional force . But since the end of the Cold War , they have not invested heavily in anti-submarine warfare capability . They are not alone in this regard -- many of the other European nations have likewise cut back in this area given a sense that anti-submarine warfare was something they would have needed against the USSR during the Cold War but less so during pre-Ukrainian crisis days with Russia . And although Sweden is not a NATO member , meaning this operation is a national effort , it is a very strong partner to NATO and has been involved deeply in positive ways in Afghanistan , the Balkans , Libya and other operations . Yet the fact remains that there is no treaty obligation on the part of NATO to be involved . If the Swedes ask for help , it is likely that NATO would respond , but to date they have not done so . Ultimately , though , we may never know exactly what has happened . It is entirely possible that a Russian submarine was performing an intelligence-gathering operation , and that it had a period of distress that alerted Swedish authorities to its presence . It may have sorted out its challenges and slipped away . Or it may be still operating in close while Russia sorts out a plan of action . The most recent volley from Russia , that it might be a Dutch submarine , seems highly unlikely . If it was any other nation 's boat , they would have likely worked with the Swedes immediately if their vessel was in distress . The Swedes , who are capable and professional , seem insistent on their concern about an unknown undersea vessel . And the reality is that they have no reason to make any of this up , instead forthrightly reporting what they are seeing . With this in mind , NATO should offer to assist with other assets and help sort out the situation , especially if there is any possibility of a vessel in distress -- no matter what the circumstances of its presence in the Baltic .
James Stavridis : Swedish media reported undersea signals , possibly Russian , off coast . Sweden denies this , he says . Swedish Navy searching , but rocky sea bottom can hide signals . He says Sweden not NATO member , but may seek help . Navy , Air Force had budget cuts . Stavridis : NATO may offer to assist , especially if it finds out a vessel is in distress .