There were many more patrols from the USN and other Nato countries in and out of the Black Sea before Russia invaded Ukraine in February 2022. Since the invasion, both the USN and Nato warships have been missing in action and the number of patrols is minuscule. It is almost as if Biden has instructed the USN not to have a presence in the same ocean as occupied by the Russians.
The lack of USN and Nato presence in the Black Sea surely sends Putin the wrong message. It conveys that under orders from Biden, the USN will seldom patrol the area out of fear of provoking the Russians. It is this same fear of escalation that Biden had when he blocked the Ukrainians Mig-29s from Poland after Putin used his "nuclear threat card". Putin is playing President Biden's fears of escalation to his own advantage to get the upper hand in the war.
What Should Be Done
Part of the problem and solution is Turkey, a quasi-Nato member that controls access to the Black Sea under an outdated treaty. Basically, Turkey denies or grants ships entering the Black Sea based on many things in order to control shipping traffic in the congested straits through which ships pass through. The problem is that Turkey is also friends with Russia on a too close basis. They have partnered in the Mideast on issues and in North Africa. They are not a dependable ally and frequently against other Nato members! Turkey really serves little value to Nato now as it acts only in its own interests.
Russia is gradually destroying 25 tons of Ukrainian grain in silos and warehouses located in the Odessa area. They have stolen some of it and sold it to African nations. To prevent the Ukrainians from exporting grain, Russia has blockaded the two main ports for Ukraine besides putting mines off shore. Of course, the Ukrainians also put mines off shore in order to prevent Russia from using the same ports!
To stop this, the USN and Nato should create a humanitarian convoy consisting of international transport ships escorted by US and Nato warships to and from Odessa ports carrying the grain. The Ukrainians would gain access to their grain markets as was done before the invasion giving them needed income. The Russian Navy would not dare take a shot in such a situation has it is humanitarian and no threat to Russian naval presence. If they intervened or fired, the USN would respond. Of course, the Russians have mined the area around Odessa and it would need to be cleared first. The British are discussing the convoy possibility with Nato members but the risks are high. A safer solution already working is to provide Ukraine with Harpoon antiship missiles and allow them to knock out Russian ships in the port areas making it costly for Putin. They have already used in this manner.
The risk is great, for sure, but not doing anything is only playing into Putin's war plan. If Turkey refused to admit the number of ships in the convoy to the Black Sea, it is time to revoke this outdated treaty and send them through.
Even if there is such convoy to save the Ukrainian grain, the absence of the USN and Nato in the Black Sea is simply bad Biden policy. The last USN ship in the Black Sea was back in January.