Your boyfriend apparently was convicted of Driving While Intoxicated (you don't say where that occurred, but I will assume it happened in Washington, D.C.) after he left the US for Poland and entered the Army. Now, he wants to go to England? and wants to know if he will be arrested due to the Warrant that's outstanding against him.
If there is a Warrant out for him, he is likely to be arrested. Of course, we don't know whether he was convicted of a Misdemeanor or a Felony, so that would make a big difference. I suggest he consult by telephone with a local attorney in the jurisdiction where he was charged with the DWI and have them arrange for a voluntary surrender so he can work the entire matter out and get it properly finished so there will no longer be a Warrant out for his arrest.
Nonetheless, it would appear he would be stopped at the airport if that airport is in the US. What they do with him after that depends on a lot of facts which are not in your question. You may want to give more detals next time.
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I agree with Mr. Robinson. If there is a Warrant out for his arrest, it is possible that he will be arested at the airport.
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